I feel like the current version of Spriests is a bit of a missed opportunity in terms of class design. They tried to create slightly different take on the whole builder-spender design that many other specs use, but things like STM have gotten out of control (from design point of view). How's this for a crazy idea:
- Entropy: New resource replacing Insanity. An ever building resource that needs to be used or else you risk triggering...
- Surrender to the Void: (Passive) Activated if you spend too long at high Entropy. You become a Void Lord. Like current STM but when SttV ends you don't die instead you become...
- Naaru: Unable to do damage but able to aid allies. Modest healing and perhaps damage increase aura. Or may be a channel spell that targets one ally incresing their damage by x% for the duration of the channel. Ends if killed or upon exiting combat.
I think removing STM from talents will make it easier to balance, both STM itself and 100 level talents in general.