Zeraora @ Life Orb
Ability: Volt Absorb
EVs: 252 Atk / 4 SpA / 252 Spe
Naive Nature
- Plasma Fists
- Close Combat / Fire Punch
- Hidden Power [Ice]
- Volt Switch / Fire Punch / Knock Off / Grass Knot
Plasma Fists is of course STAB, giving Zeraora a niche as one of the few viable physically-attacking electric types in the whole game. It has a 100 accuracy and base power with no drawbacks, and while its secondary effect of turning Normal moves into Electric isn't that useful, it's not like free bonuses to an already great attack is a bad thing. Close Combat is a powerful move that provides always useful Fighting-type coverage. Hidden Power Ice, while not being an especially powerful move, can still get the job done on weakened Pokemon such as Garchomp, Landorus-T, or Gliscor, 2HKOing them all, and possibly getting a kill or forcing them out if they set up rocks assuming you'll switch (although with how common scarfed Landorus is staying in is always a gamble).
The last move is very variable, as there aren't really any amazing choices that pop out as must haves. Fire Punch does more damage to Ferrothorn, Mega Scizor, and Kartana (max HP Kartana can actually still live Fire Punch some of the time), and can even replace Close Combat if you wish to keep one of the other moves, but generally isn't powerful enough to warrant taking. Volt Switch, my personal pick, is a decently powerful move that gives Zeraora another way to hit Pokemon specially, as well as making use of its insane speed to keep up momentum and switch to a Pokemon more suited to the situation. Grass Knot can be used to do much more damage to Hippowdown while OHKOing Mega Swampert and Seismitoad, but also usually doesn't threaten enough Pokemon to be worth taking.
Knock Off hits Mew, Lati@s, and in particular Jirachi harder than anything else Zeraora can use, in addition to removing items, which is always helpful. Here are some calcs, for your viewing pleasure.
252 Atk Life Orb Zeraora Plasma Fists vs. 248 HP / 0 Def Magearna: 172-203 (47.3 - 55.9%) -- 75% chance to 2HKO
252 Atk Life Orb Zeraora Fire Punch vs. 248 HP / 124 Def Scizor-Mega: 265-312 (77.2 - 90.9%) -- guaranteed 2HKO
0 SpA Life Orb Zeraora Grass Knot (120 BP) vs. 252 HP / 176 SpD Hippowdon: 242-286 (57.6 - 68%) -- guaranteed 2HKO after Leftovers recovery
252 Atk Life Orb Zeraora Plasma Fists vs. 0 HP / 0 Def Tapu Koko in Electric Terrain: 164-194 (58.3 - 69%) -- guaranteed 2HKO