I don't remember the rabbit's stats, but I'm pretty sure it one-shotted me. That being said, I think I was like lvl 13. Lvl 20 feels a bit overlevelled for the Phoebe section
lvl20 felt really cozy as long as you're being strategic. For the bunny, it was definitely not enough, I just came up with a really good strategy but haven't bought any healing items at that point at all. If I had, I think I could've done it