Ok what if Tony's snap didn't kill Thanos? Say instead of killing him he sent him back to the time he came from. Here's why I think it's plausible. All through out Infinity war Thanos brought up a handful of times that he knows what it's like to lose, and his Destiny being denied once, how he's cursed with knowledge, yadda yadda. He also knew how he was going to die at the beginning of Endgame that's why he destroyed the stones so he wouldn't be tempted to change his fate. What if getting dusted doesnt kill you it just transports you through time either forwards or back? Could that be what happened? Sorry for the format or what ever I'm on mobile