All of them. It either doubles the souls you’ve earned for each movie or you lose them all.
Wow, that could be even better than Barbossa if you can double up multiple times, not to mention helping if you can get to multiple wizard modes… Just don’t lose!
Thus why you use Davy Jones for that strategy. Greater odds of better dice to play with, or at least that’s my understanding of it.
The way it works right now, and is unlikely to change, is that Davy rolls 10 dice and keeps the “most interesting” 5. Normally, you keep 5/6, and the cpu keeps 5/7 (seriously the only “cheating” it does).