Looking at the Twilight book reminded me of something: this is an open universe for player creativity. Anything that's in the castebooks is the sort of thing a player can introduce. Except Spine-Shattering Bite. For example, there's a spell in the Twilight book: Summoning the Seven Secret Judges of the Hidden Flame.
The spell summons one of the seven spirit-judges who preside over the world during Calibration and prevent all-out war in Heaven. You give him a name and he goes forth to enforce The Mandate Of Heaven against him. There's a bunch of description of the cool schtick the judges have --- about a page of dense text, including stats for a Judge. The neat thing is, there's been NO WORD of these beings before. The person who wrote this up invented the whole thing.
And the rest of you can do so as well. Come up with spells, charm trees, artifacts, hearthstones and your characters can have them.
CharmHacking Thought experiments and development in progress