You know, at first I thought the whole defeat the seven forms of Sinbad thing was silly. It’s a very shounen way of handling a “final battle” plot. However, after reading a translation of chapter 336 I’m starting to find it interesting nonetheless.
Each form of Sinbad is looking for a specific answer and it appears that only certain individuals will be able to provide it (either alone or in combination since there are only four people fighting seven forms).
Baal Sinbad asks whether they should submit to an unreasonable fate or destroy it by force. Judar might be the best person out of the group to provide Sinbad with a satisfactory answer. I’m looking forward to what Judar says and does here.
Sinbad is asking Alibaba, Aladdin, Hakuryuu, and Judar to give him a reason to stop. “Why should I? Give me reasons. Answer my questions.” Depending on their answers, perhaps putting them through these trials is his way of moving forward with no regrets. I think in Sin’s mind they’ll either validate his decision or change his mind and he’s curious to see which it will be.