User blog comment:Fliu/Kizaru's purpose in the Fishman Island arc flashback/@comment-1595565-20110512165732

That is one reason for his being there, though I don't see why it couldn't have been Momonga or Doberman if it was just that. My guess, based on no evidence what so ever, is that Oda was being bombarded with questions like "Was Kizaru ever a vice admiral?", "Was he part of a Marine ROTC program?", stuff like that, and Oda just decided to answer it in the manga. Again, I base this guess on absolutely nothing, it's just what I'd do in a similar situation. The true intentions thing grabbed my attention too. I thought he had ulterior motives for capturing Arlong. We'll have to wait and see.