Moves
Scald is a useful STAB attack that has a decent chance to burn physical attackers such as Mudbray, Doduo, and Pawniard. Sludge Bomb is a good STAB attack that hits Fairy- and Grass- types such as Cottonee and Snubbull; the former is OHKOed and the latter is often 2HKOed. Recover provides Mareanie with an impressive amount of longevity and, alongside Regenerator, allows it to sustain itself throughout a match and stall out status-inflicted foes. Knock Off allows Mareanie to cripple switchins and support its more offensive teammates. Toxic Spikes allows Mareanie to support its teammates by poisoning foes; thanks to Regenerator, it is able to be set up consistently throughout a match. Iron Defense lets Mareanie obtain KOs without fear of being revenge-killed by Diglett when paired with a more physically bulky EV spread, set up alongside certain physical setup sweepers, and potentially sweep against physically inclined teams late game.
Set Details
Maximum HP EVs allow Mareanie to heal an extra hit point with Regenerator upon switching out, and 180 EVs in both Defense and Special Defense, a Calm nature, and an Eviolite allow Mareanie to optimize its bulk and tank powerful hits such as Snivy's unboosted Leaf Storm, Staryu's Psychic, and Ponyta's Wild Charge. If Iron Defense is run, the EV spread should be changed to 116 HP / 180 Def / 12 SpA / 180 SpD with a Bold nature, as this allows Mareanie to survive Diglett's Tectonic Rage after being Knocked Off at +2 Defense, and the extra recovery from Regenerator is less important. 92 EVs are invested in Special Attack to OHKO Eviolite-less Snivy, with the remainder dumped into Attack to slightly boost the power of Knock Off. However, 80 SpA EVs can be moved to Spe for an EV spread of 196 HP / 12 Atk / 100 Def / 12 SpA / 100 SpD / 76 Spe to tie with fast Timburr and outspeed slower variants of Mudbray, at the cost of a variety of damage rolls gained from 12 SpA. Regenerator is the preferred ability, as it allows Mareanie to switch out of attacks that threaten it, such as Mudbray's Earthquake or Abra's Psychic, and recover in the process.
Usage Tips
Thanks to its Regenerator ability, typing, and good bulk, Mareanie is able to reliably switch into a plethora of fearsome attacks such as Mienfoo's High Jump Kick, Spritzee's Moonblast, and Rufflet's Superpower. Regenerator should be taken advantage of whenever possible, such as when threatened by a powerful attacker like Abra or when you predict a switch to a foe that threatens it. Because of Regenerator, Mareanie should try to avoid using Recover when it doesn't need to in order to preserve momentum. Because Mareanie forces switches against common Pokemon in Mienfoo and Ponyta, it often has access to free turns, which it should use to set up Toxic Spikes, try burning switch-ins with Scald, or recover. Despite its good bulk, Mareanie has glaring weaknesses to Ground-, Psychic-, and Electric-type attacks, which means it should pivot out of Pokemon with these types of attacks to avoid taking severe damage that compromises its tanking capabilities. Don't be conservative about using Haze if running it; it's better for Mareanie to use Haze and have the opponent KO it, as this will allow Mareanie's teammates to safely revenge kill a foe that hasn't accumulated any stat boosts. Mareanie is very reliant on Eviolite, and as a result, must be wary of super effective coverage options from the likes of Mienfoo and Timburr after having its Eviolite removed by Knock Off. Mareanie should also always be wary of Guts Timburr, as it is a prevalent threat that receives an Attack boost from status, thus discouraging the use of any of Mareanie's status-inflicting moves. Lastly, Mareanie should be wary of switching into a pivoting attacker such as Mienfoo or Pancham if Diglett is on the opposing team, as it will trap and KO Mareanie.
Team Options
Mareanie's poor Speed and passiveness often mean that it fits best on slower-paced teams due to otherwise being a less useful pick than Skrelp. Ferroseed is a fantastic teammate, as it appreciates Mareanie's Fire-type resistance, is able to provide additional entry hazards with Spikes or Stealth Rock, and it is able to come in on the Ground-, Psychic-, and Electric-type attacks that Mareanie hates taking. Diglett is also a good partner, as it can make use of its Arena Trap ability to trap and remove foes that absorb Toxic Spikes such as Alolan Grimer and Stunky. Pokemon that are capable of switching into or KOing Psychic-types, such as Ferroseed, Pawniard, Magnemite, and Carvanha, all make for fantastic partners that can help Mareanie ease the pressure that Psychic-types like Abra and Slowpoke put on it, while Electric-type checks such as Onix, Drilbur, Diglett, and Chinchou are all either able to switch into or eliminate common Electric-types in Magnemite and Elekid that Mareanie hates dealing with. Grass-types such as Snivy and Cottonee appreciate Mareanie's ability to tank Bug-, Ice-, Fire-, and Poison-type attacks. In return, Mareanie appreciates the aforementioned Pokemon's abilities to switch into Electric- and Ground- type attacks that it hates taking. Fairy-types such as Spritzee and Snubbull appreciate Mareanie's ability to tank the Steel- and Poison-type attacks that threaten them, while Ghost-types such as Gastly, Pumpkaboo-XL, and Honedge are useful teammates for Mareanie because of their ability to prevent users of Rapid Spin from removing Toxic Spikes. Mienfoo, Buneary, and Ponyta are all examples of Pokemon that appreciate the Toxic Spikes support Mareanie provides, as it helps them break through bulkier threats. Lastly, if Mareanie isn't running Haze, it appreciates other phazers such as Hippopotas and Munchlax as teammates, as its team won't be as vulnerable to threatening setup sweepers.
