AKA making battles seem to drag on. One of my favorite setups is: Stall? (Shuckle) @ Leftovers Ability: Contrary EVs: 252 Def / 252 SpD / 4 Spe Calm Nature IVs: 0 Atk - Toxic - Infestation - Rest - Shell Smash Contrary allows shuckle to buff defense instead of attack. Toxic and Infestation is for killing them, and rest is to make Shuckle even more OP. Low on HP? Use rest. Leftovers are a big help too, by healing even more. It`s a super fun stall set to use, for it`s ability to really never die.
I hope @Magpie has been able to forgive me for using this all those years ago: Umbreon @ Leftovers 252 HP/6 DEF/252 SP.DEF Calm - Toxic - Mean Look - Rest - Taunt/Snatch Trap an opponent, hit them with Toxic, spam Rest until they die. Taunt and Snatch stop the trapped target from healing themselves or trying to boost stats while the poison works its magic. This was back in Gen IV, before Umbreon had access to Foul Play.