#9 Toru Yano

An originator of CHAOS alongside Shinsuke Nakamura, he isn't one to balk from betrayal which he did to Tanahashi years ago. It'd make an interesting case for Yano as the mole and revert to his more heelish serious roots of old. It would also make sense if Yano got involved with the angle because there's no doubt Tanahashi and he still have issues.
Yet the doubt of Yano joining Bullet Club works two-fold. First of all his partnership with Ishii holds strong and is, in fact, paying off at the height of the World Tag League. While it's doubtful they make it to the end, Yano is bound to not betray Ishii especially in consideration that he'd get beaten down for it. Though with the way the Best Friends are interacting, Yano turning on Ishii late into the tournament is a surprise we wouldn't see coming.
The second factor is Yano's comedic persona, the talented DVD seller is a fascinating addition to New Japan's singles talent list. A comedic force unlike anyone else in the company, Yano aids a lot in his current version (one most likely to remain as is) especially as a breather during the hectic G1 Climax. This one remains far from likely.