I dunno. It kinda sounds like a general overuse of his guilt tripping powers to suddenly kill Divine in the middle of the Aki/Misty duel part deux. It makes it look a bit like a plot device, methinks. Unless he is still DS'd at that time, somehow, then I could see that happening. I'd like to think that his powers coincide with his emotions towards them-if, perhaps, that duel with Jack/Crow/whoever helps him to see reason, and to come to terms with his powers, the responsibilites they come with, the things they've caused, and to learn to not run from them by seeking death, but accept them, and to tame them, those powers would melllow out somewhat-at the very least, stay under control better.

Now, if the duel concludes in a draw due to Yuu's powers, like Icey said, then it would be the effects of the lethal rainbows Momentum and the souls trapped within, that caused him to die, that the cause of Yuusei's death might possibly be Yuusei himself, as he wishes to seek repetenance. If Jack/Crow/whoever makes him see reason during that duel, then I'd hazard a guess that perhaps, yes, a duel might just reverse it through da powah of friendship and bonds and yaaaaaaay.