Stunfisk @ Leftovers
Ability: Static
EVs: 228 HP / 100 Def / 136 SpA / 44 SpD
Modest Nature
IVs: 0 Atk
- Stealth Rock
- Yawn
- Earth Power
- Discharge
Oh fuck. Please don't kill me. Hear me out pls :v
Serperior has quite a few enemies, that being Flying types such as Talonflame and Tornadus-T and fast Electrics with Fire and Ice coverage, such as Mega Manectric, Thundurus and Raikou. Fisky over here happens to be a Stealth Rocker that can act as a solid answer to both of those offensive groups. HP Ice from Specs Raikou, for example, fails to 2HKO this set. If anyone's asking, yes. Fisk is fat as hell. 109/84/99 bulk means he can eat up hits fairly well on either side of the attacking spectrum. Yawn can act like a pseudo phasing move. Hit the opponent up with a yawn, and they're more often than not likely forced to switch out fearing Sleep status. I will admit; it's a bit matchup reliant, not working on mons already status'd, but it's pretty effective when it works
as you can see from the replay here. Yawn also means that the likes of Zapdos will have trouble trying to Defog while you're in play, and when it has to Roost, it's vulnerable to Earth Power.
Torn-T or the incredibly bad Banded Talonflame will more often that not go for U-Turn predicting your Stunfisk switchin, but they're risking a 30% Paralysis chance on contact thanks to Static.
Serperior does NOT like SpDef Talonflame, not even being able to 2HKO at +2 with Dragon Pulse after leftovers recovery. This Stunfisk set can beat it fairly easily, since it doesn't care if it's Taunted. Keep slapping Talonflame with Discharges until it has to Roost. That's when you go for the throat with Earth Power.
228 HP EVs give Stunfisk a Leftovers number of 416, maximizing recovery each turn. 44 SpDef allows Stunfisk to dodge a 2HKO a Specs Raikou's HP Ice and a M-Diancie's Moonblast. 136 SpA and Modest OHKOs Mega Manectric and Mega Diancie after Stealth Rocks, 2HKOs SpDef Talonflame with either STAB option and 2HKOs AV Raikou after Stealth Rock. The rest is invested in Defense to give Stunfisk better mixed bulk.