The casualty Dragon brought with him to be treated was Sabo, Well that's what I think Here are the reasons why?
1.Dragon watched the Celestial Ceremony.
2.Sabo was the only clear casualty during the occasion.
3.Dragon saw something in Sabo when they met before.
4.Sabo's as tough as they come heck even being blown like that there's a chance he escaped.
5.Sabo being alive will be good for the story. Idealistic but at the same time its possible..