[ This is territory she isn't so versed in — trying to keep someone alive who really should be dead. But if this is something D really wants to do, she will rack her brain for him. She can only speak from her own area of expertise. ]

Well... his missing soul is the key to everything, isn't it? Reincarnate won't work without it.

[ A beat, and then she continues more slowly. ]

Assuming his soul hasn't been destroyed already... It isn't impossible that it's already residing somewhere else. In a different body, I mean.