I'm not a Hiruzen hater. I'm quite a fan actually drew a pic of what it would look like for him to be in sage mode. (if he could) anyway. Edo tensei can be defied as we know since juubito can turn all ninjutsu into nothing. Thus most physical attacks and ninjutsu won't work. Naruto:sage mode Tobirama: knowledge, FTG Minato: Ftg Sasuke: That bastard always has something sneaking planned. So if he could some how use senjutsu or if he would be used as a decoy there's nothing for him. (I think he's still alive since obito never fully controlled the jubi. Thus not having the ability to nullify ninjutsu. So I think he's still generating)