Been DYING for Grumpig, I have the funnest set I've been running with that thing that is really lol and fun to use.
Grumpig @ Macho Brace
Trait: Thick Fat
EVs: 252 HP / 4 SAtk / 252 SDef
Calm Nature (+SDef, -Atk)
- Trick
- Psychic
- Reflect
- Light Screen
My preferred choice for the massacre of mixed infernape. Macho Brace will slow down anything, and is also great for Hera switch-ins.
Then it pseudo-passes to a sweeper to allow it to takes hits while you wipe out a pokemon or two. You can also run the likes of Grass Knot over Light Screen for attacking options against swampert and the likes.
Oh, Gengar will always try to shadow ball you, which will result in quite the speed drop lol
EDIT: As is Twave, sims' post reminded me of that :P
EDIT 2: Thunder Wave is actually really good for slowing down an entire team.
But also, if you're lucky enough to trick macho brace onto a choice item user, you can use a trickband strategy later. For example, if you trick with a specmence, you can come in later and use trick to put choice specs onto something like a steelix. It's fun to play around with.