>>27064897time traveling hi jinks like slitting your throat when you're an infant likely don't work on on deities like a reaper, so that's out.
and in a direct confrontation, a reaper obviously has a strong advantage in all physical stats when compared to standard ame who at most has a gun and a syringe.
Ame's likely only 2 chances at victory would be to time travel to the height of humanity and take the most powerful combat tech humanity has ever created and use that against calli. her other option would be to travel to the past and look for rituals and the like that can be used to seal or bind demonic entities, maybe one would be effective enough to seal away calli, especially if used on her weaker younger self.
