My Little Pony: Friendship is Magic - Image #482,038

OP fails to recognise that having a stake is exactly what the process of socialisation is. Society gives us things, experiences, most of all friends and family these stakes are what involve us in social processes until they are internalised. So the change is very real, not dramatic total conversion, but he cares about someone outside himself now, that's pretty big even if the trickster personality remains.

i still wonder what celestia wants to use him for