Grass / Ghost
Because it can run boosting, non-boosting attack based, and non-boosting status based sets equally effectively, and I do mean equally. Defensive weaknesses are less important than defensive resistances, as the metagame has taught us over and over again (Raikou has great stats, everything it needs in terms of movepool, and only one weakness, and it's UU). And while I'm at it, shinyskarmory's premise that Grass is a terrible offensive and defensive type suggests to me that he does theorymon much better than he plays the actual OU metagame.
Because it can run boosting, non-boosting attack based, and non-boosting status based sets equally effectively, and I do mean equally. Defensive weaknesses are less important than defensive resistances, as the metagame has taught us over and over again (Raikou has great stats, everything it needs in terms of movepool, and only one weakness, and it's UU). And while I'm at it, shinyskarmory's premise that Grass is a terrible offensive and defensive type suggests to me that he does theorymon much better than he plays the actual OU metagame.
