Poliwag can be found in Brooklet Hill and the Malie Garden in both games. In Malie Garden, it can only be found in the grass, whereas in Brooklet Hill it can be found both in the grass and the water. Poliwhirl and Politoed can be found in the wild, but only in Malie Garden as a SOS chain encounter under the rain, and Politoed can only be found at night; a Poliwhirl may be traded for a Zubat in Konikoni City.
King's Rocks may only be found attached to wild Slowbro, Poliwhirl, Politoed, and Poliwrath in the game. Wild Slowbro can be encountered via chain-SOS in Kala'e Bay, while Poliwrath is available only in Malie Garden during the day under the same conditions as Poliwhirl.
Getting a Politoed requires supreme dedication: chaining for a King's Rock is more than just hard, as opposed to simply picking up a Water Stone or buying it in Konikoni City. Compared to Poliwrath, Politoed likely has better damage output; there is no physical Water STAB available until the postgame, and Poliwrath is only mildly content with Scald, which is very good on Politoed instead. Aside from Scald, though, Politoed gets nothing but Psychic, and there are no status moves it can learn to boost its stats, either. With all the Water competition coming from the entirety of Alola, even the likes of Pelipper with the newly acquired Drizzle, Politoed remains a "good but not great" Pokémon; it is worth using with Water Absorb as its ability, which hard-counters some of the scariest Pokémon in the game, but Damp specimens get the short end of the stick under several evaluation parameters.
Totem Wishiwashi (Brooklet Hill): A Damp Poliwag stands no chances against Totem Wishiwashi, which deals almost three times as much damage with Water Gun than Poliwag can do with Scald. A Water Absorb Poliwag, instead, makes the fight completely trivial, being vulnerable only to the ally Wishiwashi's Feint Attack, a weak move that takes several turns to KO. Alomomola can also hit Poliwag, though, so Poliwag should nevertheless beat Totem Wishiwashi first and the ally Wishiwashi later; Alomomola will not be called into battle if Totem Wishiwashi is over half its HP after the first turn, and then defeated before the ally Wishiwashi is.
Battle Royal (Royal Park): Poliwag's Scald can OHKO Rockruff with a good damage roll, but it is risky to use Poliwag in this battle, as the combined moves of the three enemies can take it down if one of them is a critical hit. This assumes Hau has Torracat or Brionne; if Hau's starter is Dartrix instead, the stakes are too high for Poliwag to take part in this battle.
Totem Salazzle (Wela Volcano Park): Although Scald has reasonable chances to 2HKO Totem Salazzle, Poliwag is unlikely to last more than one turn. Flame Burst is a 3HKO in spite of the resistance, and if Poliwag is poisoned, the ally Salandit - which are summoned continuously, regardless of how many are defeated - can even OHKO with Venoshock. Only Scald-powered Hydro Vortex has good OHKO chances, but in the event the OHKO is not scored, Poliwag is likely to need a switch-out.
Totem Lurantis (Lush Jungle): The Totem's Solar Blade is overkill against Poliwag and Poliwhirl, and guaranteed to OHKO even Politoed in one shot. None of the evolutionary stages should participate in this battle.
Plumeria (Akala Outskirts): An Eviolite Poliwhirl averagely scores a 3-4HKO against Golbat and a 1-2HKO against Salandit with Scald; Politoed scores a certain 3HKO and OHKO respectively, though it may also fall prey to Golbat's Confuse Ray, being slower than Poliwhirl.
Olivia (Ruins of Life, Rock-type): A Poliwhirl carrying the Eviolite can win the matchup by 3HKOing Nosepass and 2HKOing Boldore, then 2-3HKOing Lycanroc, all with Scald. The strongest move is Lycanroc's Continental Crush, which can deal over half in damage without a critical hit, putting Poliwhirl in the safe 3HKO zone if it is healed at least once, since Rock Tomb will deal approximately half that damage; since Poliwhirl's Speed is higher, a healthy Poliwhirl will defeat Lycanroc without a problem with good Speed investment, but even a Speed-lowering nature can compromise outspeeding since Lycanroc has full EV investment in the stat. Politoed also 2HKOs the first two Pokémon, which have Sturdy, and takes slightly more damage from Lycanroc, but its Scald is a certain 2HKO against it. Poliwhirl loses from forgoing the Eviolite in favour of the Waterium Z, which does not allow the OHKO against any of Olivia's Pokémon; Politoed, instead, can use Hydro Vortex to OHKO Lycanroc.
Lana (Konikoni City, Water-type, optional): An Eviolite Poliwhirl has trouble against Chinchou, whose Electro Ball is far too strong even at its minimum base power, but easily beats Shellder with Body Slam; it is once again disadvantaged against Araquanid, which has far greater bulk. Politoed can win against Chinchou if it knows Body Slam, which 3HKOs, but Chinchou's Electro Ball also does and Chinchou may outspeed even Politoed, since its Speed has maxed out EVs. Araquanid remains stronger and may only be defeated if Politoed's Scald scores a burn within a couple turns, and Politoed is kept healed as it fights.
Kiawe (Royal Avenue, Fire-type, optional, Sun only): Both Eviolite Poliwhirl and Politoed do well against Kiawe. The former 2HKOs Growlithe and Fletchinder and 2-3HKOs Marowak with Scald, while the latter OHKOs all but the ace, which is 2HKOed, or OHKOed with Hydro Vortex.
Mallow (Lush Jungle, Grass-type, optional, Moon only): An Eviolite Poliwhirl does poorly against Shiinotic and is disadvantaged against Steenee, despite Steenee's low Special Attack supported only by Magical Leaf; it can theoretically beat Phantump with Scald and some patience, but Phantump's lack of Grass STAB is nevertheless compensated by the annoying Leech Seed, so having Poliwhirl fight against Mallow is not recommended. Politoed has slightly better stats, but faces the exact same struggles against Mallow's team.
Nihilego (Aether Paradise): Poliwhirl cannot win even with the Eviolite, though it cannot be killed in one hit either, so heal stalling until Nihilego runs away is possible. Politoed, instead, can 3HKO Nihilego with Scald, or 2HKO with a combination of Scald and Hydro Vortex.
Hau (Malie City): Neither Poliwhirl nor Politoed may win against Raichu in any way; they also lose against Leafeon or Dartrix, both of which pack strong Grass moves, Giga Drain and Bloom Doom respectively. Both have an edge against Vaporeon with Body Slam; Politoed finds the matchup easier, though the greatest determinant is the ability, as Water Absorb will void Vaporeon's Water Pulse, removing the chance of confusion and leaving only Quick Attack for Vaporeon to hit with. A similar matchup is attained against Brionne, which cannot use Hydro Vortex against Water Absorb Poliwhirl/Politoed. Beating Flareon and Torracat is fairly trivial for both evolutionary stages: Poliwhirl scores a 3HKO and 2HKO respectively, on average, while Politoed is set at 2HKO and 1-2HKO, the latter skewed towards the OHKO. Hydro Vortex is a likely OHKO against Flareon, and a guaranteed one against Torracat.
Totem Vikavolt (Hokulani Observatory): Totem Vikavolt knows Spark and so does its second ally Charjabug. Given that the move 2HKOs even Politoed at worst, OHKOing for certain with a critical hit, neither Poliwhirl nor Politoed should be fighting here.
Guzma (Malie Garden): Politoed should be fully evolved by now. Only Water Absorb Politoed should fight Golisopod; Protect is necessary on the first turn, to avoid getting hit by First Impression, but even Razor Shell is almost as strong as Politoed's Psychic if Politoed is not immune to Water, and completely outclasses Psychic after a single Swords Dance, resulting in a 3HKO (2HKO after two Swords Dances). Psychic is a clean 2HKO against Ariados as well, though Politoed should not tackle it below 30% health due to Sucker Punch.
Totem Mimikyu (Thrifty Megamart): Totem Mimikyu 2HKOs Politoed flat with Play Rough, and Politoed can barely do less than half of that damage with Scald. Even a potential burn would be cancelled out by Mimikyu's Lum Berry, so Politoed should just avoid fighting against the Totem.
Plumeria (Route 15): Politoed's Psychic 2HKOs Golbat, though its Confuse Ray may slow down the battle in the process; Shattered Psyche OHKOs instead. Salazzle is 1-2HKOed by Scald, or OHKOed by Hydro Vortex.
Guzma (Shady House): Politoed can fight Golisopod only if its ability is Water Absorb; in this case, Protect shields it from First Impression on the first turn, and it can then weaken Golisopod with Psychic. Damp specimens will be outdamaged by Golisopod's Razor Shell even without any Swords Dances, and there is near-certainty of Golisopod killing them off even if healing items are being used, due to the increased critical hit rate of the move. Ariados, instead, is 2HKOed by Psychic or OHKOed by Shattered Psyche regardless of ability.
Gladion (Aether House): Politoed can 2HKO Golbat with Psychic, but will also be severely damaged by Acrobatics; a critical hit and a regular one may even kill Politoed. This can be avoided with Shattered Psyche, which OHKOs. Sneasel is OHKOed with Brick Break; the move is only a 3-4HKO against Type: Null, however, which is better weakened with Scald in hopes of scoring a burn. If this does not happen, Politoed will need to switch out after a single Defense drop from Crush Claw, as from two drops onwards Pursuit becomes a threat. If Politoed can still use its Z-move, a combination of Hydro Vortex and Scald is likely to KO Type: Null in three turns, reducing the risk.
Nanu (Malie City, Dark-type): Politoed 3HKOs Sableye with Scald and also OHKOs Krokorok with it. It is recommended to let Politoed hold a Persim Berry or Lum Berry; Krokorok may use Swagger, and is nearly guaranteed to outspeed Politoed. Regardless of Swagger usage, Scald is more powerful than Brick Break against Persian, which has Fur Coat; the move is a 2-3HKO against Nanu's ace, though Persian can also 3HKO if Politoed is not healed after taking Black Hole Eclipse from it, or even 2HKO with two consecutive high damage rolls of the Z-move and Dark Pulse. Hydro Vortex and Scald will 2HKO Persian when combined, but holding the Z-Crystal will hinder Politoed against Krokorok's Swagger.
Faba (Aether Paradise): Scald and Hypno's Psychic have almost the exact same base power. Politoed will generally outspeed, unless its nature detracts from the stat, but Hypno will win if Psychic causes the Special Defense drop. Since both moves are a 4HKO on average, backup should be prepared in the event that Politoed needs to be switched out. Alternatively, one Hydro Vortex and two Scald will KO Hypno.
Faba (Aether Paradise, tag battle with Hau): Politoed is not the ideal candidate to start the fight: Ledian has good special bulk, and Slowbro resists its best moves as well as having good physical bulk, thereby taking little damage from Body Slam. It is recommended that another Pokémon take down Ledian first, especially since it can set up both Reflect and Light Screen. For reasons similar to Slowbro, Politoed should not fight Bruxish: unless burned by Scald, its Psychic Fangs will be a 2HKO not too far from an OHKO, and none of Politoed's moves can inflict significant damage to it. Hypno now has full Speed investment and its Psychic is about as powerful as Politoed's Scald; Politoed will generally lose against it, but may win with healing support or by using Hydro Vortex if Psychic does not cause any Special Defense drops.
Guzma (Aether Paradise): Only Politoed with Water Absorb should take on Golisopod, as they will otherwise be outclassed by Razor Shell and further endangered by possible Swords Dance spam; Water Absorb specimens must still start with Protect to dodge First Impression damage, and can then weaken Golisopod with Psychic. Ariados can be 2HKOed easily with Psychic, or OHKOed by Shattered Psyche, but Masquerain beats Politoed with Bug Buzz and can even outspeed; same for Pinsir, but with X-Scissor instead of Bug Buzz. While Masquerain is 2HKOed by a combination of Hydro Vortex and Scald, Pinsir would still 2HKO and is impossible to beat.
Lusamine (Aether Paradise): Clefable's full HP and Special Defense EV investment make it an impossible opponent for Politoed, whose moves would deal next to no damage; Politoed must also avoid Lilligant, which would kill on the spot with Petal Dance. Mismagius beats it with Shadow Ball, a 3HKO against Politoed's likely but not certain Scald 3HKO, on top of its lower Speed; even Hydro Vortex and Scald combined cannot achieve a certain 2HKO, though the probability is high. Milotic outdamages with Hydro Pump if Politoed has Damp, but can be beaten by Water Absorb specimens easily, only watching for the damage dealt by Psychic as Milotic should not be reduced to 1HP or thereabouts, to avoid its Flail hitting with maximum power. Politoed of any ability can beat Bewear, 2HKOing with Psychic; Shattered Psyche has a moderate OHKO chance against it.
Hapu (Vast Poni Canyon, Ground-type): Scald OHKOs Dugtrio and can 3HKO Flygon, but Flygon will also 3HKO with Earth Power; Politoed will win the matchup only if it heals at least once, and will be at a definite disadvantage if Earth Power eventually causes its Special Defense to drop. Alternatively, Politoed can 2HKO with Hydro Vortex and Scald combined. Gastrodon is a Scald 4-5HKO on average, but knows Recover; Damp specimens are likely to lose in the long run, while Water Absorb specimens have better chances, being hit only by the inaccurate Mud Bomb. Politoed may also win against Mudsdale, but must either save Hydro Vortex to OHKO it or correctly predict Tectonic Rage and use Protect on the first turn; if this does happen, it can then 2HKO with Scald. A Tectonic Rage from Mudsdale is a certain OHKO, so Politoed must not remain on the battlefield if the prediction is incorrect; a switch-in that is at least resistant, if not immune, to Ground moves is recommended in this circumstance.
Totem Kommo-o (Vast Poni Canyon): Politoed cannot win against the Totem, since Clanging Scales only lowers its physical Defense, and Politoed hits specially. Even Shattered Psyche takes away just barely over half of its health, which is not enough.
Lusamine (Ultra Space): Clefable is nearly impossible for Politoed to beat, having full EV investment in HP and Special Defense, as well as a +Special Defense aura; Lilligant OHKOs Politoed with Petal Dance, as well. Politoed will also lose against Mismagius unless healed; Hydro Vortex and Scald combined can 2HKO, but are not exceedingly likely to do so, and should that fail Mismagius' Shadow Ball will net a 3HKO instead. The move can even 2HKO, if the first hit causes a drop in Politoed's Special Defense. The fight against Milotic is possible only for Water Absorb specimens, which take no damage from its Hydro Pump; whittling down Milotic's health with Psychic is a long and daunting process due to its Recover, but if Politoed outspeeds, it can KO with Shattered Psyche starting at around 33% of Milotic's health. Psychic is only a 2-3HKO against Bewear, which 2HKOs with Hammer Arm, but Shattered Psyche will KO on the second turn if the Z-move can still be used.
Solgaleo (Altar of the Sunne, Sun only): Solgaleo's Zen Headbutt 2HKOs Politoed, and even Hydro Vortex cannot help against it.
Lunala (Altar of the Moone, Moon only): Lunala's Moongeist Beam is also a 2HKO. Politoed cannot win, as all of its moves deal ridiculous damage.
Gladion (Mount Lanakila): Politoed's Psychic is highly likely to 2HKO Crobat, and Crobat can only 3HKO with Acrobatics, though Politoed with lower-than-average Defense may suffer a 2HKO; in order to be certain to 2HKO Crobat, Politoed needs to use Hydro Vortex first. Conversely, Weavile can be beaten only with Expert Belt-boosted Brick Break, or All-Out Pummeling, both of which net an OHKO. Lucario can be 2HKOed with regular Brick Break, since its Aura Sphere struggles to even 3HKO. Grass-type Silvally must be avoided due to their strong Multi-Attack; Water-type Silvally is also likely to win the matchup, due to Crush Claw being stronger than Psychic and also highly likely to lower Politoed's Defense. Fire-type Silvally can be beaten with Hydro Vortex or Scald, respectively an OHKO and 2HKO.
Hau (Mount Lanakila): Politoed should not be in the lead, since Raichu's Thunderbolt would 2HKO it; it must also avoid Komala, which is likely to OHKO with Wood Hammer. Leafeon "only" 2HKOs with Leaf Blade, but Politoed is slower and its Ice Beam can do no better; Decidueye can kill even with Leaf Blade, and is guaranteed to with Bloom Doom. The matchup against Flareon is easy, since Scald 2-3HKOs and Hydro Vortex has high OHKO chances; Incineroar must be beaten with Hydro Vortex alone, since it has 2HKO chances with Darkest Lariat and even though Politoed will generally outspeed, its Scald is not guaranteed to 2HKO. Vaporeon is trivial to beat for Water Absorb specimens, but requires patience unless Psychic scores multiple Special Defense drops; Damp specimens would be on the losing end, unless they stall out Hydro Pump PPs. Water Absorb is not sufficient to win against Primarina instead, which 2-3HKOs with Moonblast.
Elite Four Hala (Pokémon League, Fighting-type): Politoed can beat Hariyama only with a combination of Shattered Psyche and Psychic, as Hariyama would otherwise defeat it with Close Combat; this may also be the only chance Politoed gets to use Shattered Psyche at all, as its Z-Crystal can be Knocked Off by Hariyama. Alternatively, Politoed may be kept in the sidelines until Hariyama is down, to OHKO Primeape with Shattered Psyche; even in this case, Primeape would win if Politoed did not OHKO, so using Psychic is not an option. Psychic can, instead, 2HKO Bewear, which is slower than Politoed; however, Politoed needs to be at 75% of its health or above to take Hammer Arm from Bewear and survive. Politoed may win against Poliwrath if it outspeeds, as both Psychic and Submission are 3HKOs; Submission is not guaranteed to 3HKO, though. Alternatively, if Politoed's Z-move has not been used yet, Shattered Psyche and Psychic will KO in two turns. Crabominable can be defeated either with two Psychics from full health, or with one Shattered Psyche anywhere below, as Politoed needs every last one of its HP to withstand Close Combat.
Elite Four Olivia (Pokémon League, Rock-type): Relicanth and Carbink are 3HKOed by Scald; Probopass is more quickly dispatched with Brick Break, which has a 2HKO chance. Politoed can 2HKO Golem with Scald and OHKO Lycanroc with Hydro Vortex, but it is unlikely to beat both Pokémon unless switched out and healed in between; it needs over 80% of its health to survive Thunder Punch for sure, and the entirety of its HP bar to live a Continental Crush from Olivia's ace.
Elite Four Acerola (Pokémon League, Ghost-type): Sableye is 2HKOed by Scald or OHKOed by Hydro Vortex, though the Z-move is best saved for stronger Pokémon on Acerola's team. Drifblim should be avoided, if better counters are available: it outspeeds Politoed, can use Amnesia, and knows both Ominous Wind and Baton Pass, a very dangerous combination; even without any Special Defense boosts, it is only a 3HKO. Dhelmise is 2-3HKOed by Ice Beam, but can 2HKO back if Ice Beam fails to KO in two turns; only Subzero Slammer and Ice Beam together can net a certain 2HKO. Froslass can be 2-3HKOed with Scald instead, since its Shadow Ball is a 4HKO at best; a switch-in or the Z-move should be ready if necessary, though, since a Special Defense drop from Shadow Ball can worsen the matchup for Politoed. Lastly, Palossand is 2HKOed by Scald or OHKOed by Hydro Vortex; Politoed's health must be 75% or above to take a Never-Ending Nightmare in the process, though, if it does go for Scald over its Z-powered version.
Elite Four Kahili (Pokémon League, Flying-type): It is advised to let another Pokémon take on Skarmory; Politoed's Scald only 3HKOs, and Skarmory outspeeds and can set up exactly that many Spikes layers before going down. Crobat is easier, being 2HKOed by Ice Beam or OHKOed by Subzero Slammer, while Oricorio is 1-2HKOed by Scald or OHKOed by Hydro Vortex. Expert Belt Scald also OHKOs, but prevents Politoed from using Subzero Slammer. Mandibuzz's Brave Bird and Politoed's Ice Beam both 3HKO; Politoed will win if at full health and faster, otherwise it will need to be healed at least once. Toucannon cannot be beaten, it will outspeed any Politoed without full Speed EV investment and OHKO with Supersonic Skystrike.
Professor Kukui (Pokémon League): Lycanroc is likely to be OHKOed only with Expert Belt Scald; else, it can be OHKOed with Hydro Vortex. Politoed can beat Ninetales with Scald eventually, but as the move is roughly as powerful as Dazzling Gleam, it will need healing once; otherwise, it may hold the Leftovers, though this prevents Z-move usage. Politoed loses against Braviary no matter what, since it can 2HKO with Brave Bird and is guaranteed to outspeed, and not even Subzero Slammer can OHKO; it must also stay away from Magnezone, which has Sturdy and can one-shot even from full health. Snorlax is also an unlikely opponent for Politoed, due to its massive special bulk and high Attack; Body Slam outdamages even Hydro Vortex by far. Politoed also gets OHKOed by Decidueye's Leaf Blade, let alone Bloom Doom, and Primarina 2HKOs with Moonblast; it can only beat Incineroar, and only with Hydro Vortex, which is highly likely to OHKO. If Politoed outspeeds and its health is 70% or more, it can take even Inferno Overdrive, which is stronger than Darkest Lariat despite the resistance, and 2HKO if Hydro Vortex does not take Incineroar down in one go.
Tapu Koko (Ruins of Conflict): Politoed will lose to Tapu Koko; Hydro Vortex cannot OHKO, and either of Tapu Koko's Electric moves will 2HKO.
Post-Game: Politoed's typing and specially-based build are not a strong asset against the largely physically-based Ultra Beasts, though it can do some work in the League rematches.
Poliwag starts with Water Sport, Water Gun, Hypnosis and Bubble at its earliest level. Since the Scald TM is also available in Brooklet Hill, its level-up Water STAB will be largely useless. At level 15, it learns Double Slap, which would normally be bad, but provides the only non-Water move available to the line in the beginning of the game; at level 18 comes Rain Dance, which boosts Poliwag's offensive power and, ironically, permits it to summon the rain-based SOS Pokémon that hold the item necessary for its evolution. At level 21, Body Slam is learned; this should replace Double Slap as the go-to non-STAB option, which has good base power and a good paralysis chance. At level 25 comes Bubble Beam, but due to Scald being already available, there is no use learning the move. Poliwhirl will attempt to learn it again at level 27. From this point onwards, the evolution into Politoed will bring stat-based advantages, but also limit Politoed's access to other moves Poliwhirl learns by level. Mud Shot comes at level 32, and while it may be a good short-term option, Politoed will not need it in the long term; Belly Drum, at 37, may be more interesting, but most Politoed will want to rely on their special moves rather than their physical ones. A good Poliwhirl-only option is Wake-Up Slap, but Poliwhirl learns it at level 43, which is already much too late for it to hold off, even with the Eviolite attached. Hydro Pump and Mud Bomb, at levels 48 and 53 respectively, are too late and arguably not worth waiting for. Politoed has only three level-up moves: Swagger at level 27, Bounce at level 37 and Hyper Voice at level 48, all of which are not very useful. Unless Politoed must run a Belly Drum-based set, the best option is to evolve Poliwhirl right away.
Politoed gets access to several TMs. Scald is a great early game move, supported by Poliwag's good Speed and STAB, but cannot be upgraded with Surf since the TM is only found in the postgame. Another must have is Ice Beam, a late game move, but great for coverage; Psychic is another good option, usually available before Poliwhirl even evolves. Physical sets would usually run a triptych based on Earthquake and Brick Break supported by Belly Drum, with Waterfall as the obvious go-to STAB move; unfortunately, said sets are not viable, since both Earthquake and Waterfall are only available after the main adventure. In any case, since Politoed's Attack is not much lower than its Special Attack, Brick Break is workable even on otherwise specially-based sets.
Poliwag gets near-immediate access to a very powerful Hydro Vortex, running off Scald. After evolving into Poliwhirl, All-Out Pummeling will also deal considerable damage to Pokémon that resist Water moves; later down the road, Shattered Psyche can power up Psychic, and towards the very end of the game Politoed also gains access to Subzero Slammer.
Grass-types: Alola is ripe with Grass-type Pokémon, many of which plentifully cover Politoed's only two weaknesses. Physically-based Grass-types are preferred, but specially-based ones also do the job well. Dual Grass-types should be preferred to pure ones, as they get an additional STAB to hit enemy Grass-types with.
Physical tanks: Even though Politoed's physical bulk is not bad, physical sweepers that are EV trained in Attack will usually be too powerful for Politoed to take their hits. For this reason, it is recommended to have a physical wall on the team.
Minimum stats are calculated with 0 EVs, IVs of 0, and a hindering nature, if applicable.
Maximum stats are calculated with 252 EVs, IVs of 31, and a helpful nature, if applicable.
What Nature do I want? Politoed makes some use of each of its stats, so natures will only matter so much, so long as they do not lower Special Attack. Since Scald is its main move, Modest or Quiet will work well on it. Special Attack-lowering natures, instead, penalise its already not excellent offensive presence.
Which Ability do I want? Water Absorb. There is a very noticeable difference in usefulness between one ability and the other; Politoed with Water Absorb are good counters for several threats, whereas Politoed with Damp end up being outclassed by far too many other Water-types.
At what point in the game should I be evolved? Poliwag should be a Poliwhirl before Olivia; from there onwards, the evolution into Politoed should happen as soon as possible, by Malie City at the latest. An unevolved Poliwhirl would struggle to keep up with the level curve from there on out.
How good is Politoed in a Nuzlocke? Quite good with Water Absorb, though only in its pre-determined niche. It can take special hits fairly well, and makes threats such as Guzma's Golisopod and Lusamine's Milotic trivial to beat. Damp specimens are just another average Water-type Pokémon, likely not worth the trouble of getting a King's Rock for.