Partner: Krush the Muk
Reasons for joining: I just wanna say I love the poison type! As far as battling I've always like that "suprise factor" trait that most of them have, or otherwise just being good at what they do best. My favorite thing about the poison type is the quirks and variety givin to them based on their descriptions, designs, and most of their anime depictions (personalities, roles, etc.) that give them their own layer of depth, occasional and humor. Examples: Ash's Muk <3, Brock's Croagunk, Gengar line trio at the tower of terror, Ash's bulbasaur (as well as others I mention by name).
Answering the topic question:
Well if i were a poison specialist for the Elite Four my team would be something like this:
Most of my favorite poison types in a bunch. Muk would be my MVP just cause hes awesome like that.