Where specific cards will fall within that range, only time will tell
Volcanic Meteor is energy-heavy, but timed well, it can be helpful to KO tanky threats that Roasting Heat cannot deal with
You may play lands and cast Bird spells from the top of your library
It turns out that Magic players love casting spells for free, even if free in this case is pay seven mana for an artifact and cross your fingers you overcome the randomness to get what you want. The silver lining, of course, is whatever spell youre copying from your graveyard gets to stay there on the chance youll copy it again, unlike many cards of this ilk that exile the spell following the resolution of the copy trigger, so if you can find a way to finesse only one legal target for the Crucibles trigger (perhaps by ensuring the top two cards of your library are lands with something like Senseis Divining Top), then youll get to copy the same thing over and over
Its a subtle distinction, but building an entire deck out of enchantments really magnifies the effect on your gameplay
