It was a shame that Bon Clay did not manage to leave Impel Down with Luffy.
Here is a list of things that Bon Clay could do if he had escaped:
- He could try fighting Hina again at Marineford.
- When he goes to Momoiro Island (where Sanji was sent flying to) with Ivankov, he can vouch for Sanji when he is trying to convince the Okama Queen that he is part of the Straw Hat crew.
- Lastly, Bon Clay could make Sanji's experience in "hell" a bit better by turning himself into Nami or any other woman he touched in the past.
If there is anything else that Bon Clay could do, feel free to say so.