mmh, i'll take another look at the specific room, maybe I missed a layer.
I'm glad the Pleasure in Power (previously Sonic Boom) jewel is still seen well, I am quite satisfied with the state of it, and I definitely want trigger-spells to be a viable playstyle.
Mana builds here have a strong focus on versatility. since mana can always be used to heal, and can also be used to damage, playing a mana-focused build allows for "on-the-fly" adaptation. Of course 1 or 2 mana jewels are attractive for most builds anyway, for the convenience of having more spells available.
So far, i'm happy with balance, because different builds shine in different ecosystems. A build that has trouble defeating the Lamia, for example, might breeze through the Burrower, and vice versa. And i'm very happy with that =D