Me and my friend were talking and she said that you can rb pets after they've been killed at a low level(EDIT: and when you train them), is that true? = w =

You revive them at any point by paying the stars, but at the rebirth quest they have to be level 100 to do the quest. My Xoalan was level 20 when I did her death quest and I had to level her to 100 to do the rebirth quest.

Ahh, thank you for the info. ;]