I'm pretty sure only 4 or 5 cards in the game get dual threat as an unstoppable c-factor, but the best two are ROLB Bo Jackson  and LOLB Ed O’Neil. 

It is like unstoppable force and every Ko on two 99 speed - 99 acceleration hell hounds when you are in 6-1. 

Ed O’Neil especially is expensive but he is genuinely the best cpu card in the game.