Most charms cost too much for any one ability to balance having multiple options, but this one uses color intensity for balance, so each effect is worth 3 mana (except maybe the combat trick)
It comes replete with a cast of pegasi, winged bulls and spear-wielding Greek soldiers
The two are comparable as four mana green legends with five-color identities due to their activated abilities, but after that, they diverge quite a lot
This abolishes the monarchy from the game
The funny thing is, Gandalf must read one of his scrolls whenever you cast an instant or sorcery spell whether you want him to or not, and one of the scrolls has Gandalf putting himself on top of your library which is the perfect place to restock his supply of scrolls for when you cast him again
Given the trajectory of Fatal Push, Id expect that Unholy Heat wont be going anywhere but up