Deoxys-Attack @ Mental Herb
Ability: Pressure
EVs: 252 Atk / 252 Spe
Hasty Nature
IVs: 0 HP / 0 Def
- Magic Coat
- Swagger
- Taunt
- Dragon Rage
Rampardos @ Mental Herb
Ability: Mold Breaker
EVs: 252 Atk / 252 Spe
Hasty Nature
IVs: 0 HP / 0 Def
- Swagger
- Whirlwind
- Toxic
- Dragon Rage
A pair of attackers that are more than capable of OHKOing themselves with confusion damage, if my calculations are correct. Their movesets are filled out with the most appropriate moves to the task at hand, really -- Swagger and Dragon Rage are mandatory, Magic Coat to reflect back opposing Taunts, Taunt to stop opposing setup, Whirlwind to reset opposing Toxic damage, and Toxic to hasten your partner's decline (since it's not carrying Toxic Orb). Mental Herbs give you a turn of setup. Ideally, though, these two will be KOed before they can do much. There's probably other things that can KO themselves that are faster than Rampardos, but the idea stays.
Thundurus @ Toxic Orb
Ability: Prankster
EVs: 252 Atk / 252 Spe
Hasty Nature
IVs: 0 HP / 0 Def
- Thunder Wave
- Swagger
- Taunt
- Dragon Rage
Prevents opposing status orbs from activating and might make the opponent waste a turn or two, and doesn't terribly mind having a Thunder Wave thrown back at it. Also, if one of the above two manages to get KOed before it can Swagger the other, Thundurus can pretty reliably ensure its Swagger activation.
Also, I'm not gonna bother to post a set, but Mega Mom's Dragon Rage + Belly Drum + Black Sludge is an OHKO on minimum HP Zigzagoon. If it gets taunted, another Dragon Rage will still finish it off.
EDIT: Any thoughts on Magic Room? If you run a strategy that isn't reliant on Sludge/Orbs (though I would suggest still running those, obviously), you can slap it on Klefki or Gothita or Mega Banette to screw up opponents whose primary method of self-inflicting is with their items. In a similar vein, Skill Swap + Poison Heal could be pretty funny, but it takes two turns and two Pokemon to set up -- there are probably faster ways to neuter Toxic Orbs.