Hmm.
The thing is, I feel it just fits too well:
- Kuzan is mentioned by Doffy to be determined and having purpose, and he's in the double spread.
- We know Imu is afraid/hateful towards Teach.
So imagine this: Kuzan loses to Akainu. He's left rudderless because he's always been inconsistent when it comes to his Justice, and he doesn't want to serve under Sakazuki.
But then the Gorosei and Imu swoop in, manipulate him into going undercover to assassinate Teach. They tell him something or the other to convince him and he goes with it.
We know that Kuzan is strong enough to defy or escape Teach if it comes down to it, and we know he can pull off "deep freezes" that can be lethal. This would make him a great choice to attack and disable Teach if he's gained the latter's trust.
I know it could all be bunk, but you know, it's fun to speculate, and the idea of Kuzan being sent as an assassin/spy to monitor/kill Teach is fun to me.
Especially if he's a triple agent who's secretly double crossing both sides.