Disintigrate (6th level + quicken)Cool. Gut reaction is that you underrate crown of stars, but I haven't closely considered the math and mechanics of it yet.
Crown of stars (7th level)
26 per turn = 78 in a 3 round battle
Spiritual Weapon (7th level)
32 per turn = 96 in a 3 round battle
Quicken + Firebolt + fire dragon sorc (convert a 7th level slot for SP).
21.5 per turn = 64.5 in 3 round (+ 1 SP left over).
Sunbeam (6th level, AoE, concentration, action, half on miss)
27 per turn = 81 in 3 rounds.
All (except sunbeam) do nothing on a miss, so accuracy not included.
So unless you get multiple battles worth, something I find dubious even with an hour, I don't see it as all to great.
Most spells don't use advantage. And there's really no other feat that makes/breaks anything. Unless you have an odd score.Are you going to look at the racial feats as well? Elven accuracy seems like an obvious winner, especially for wild magic.
But fair point about wild. And shadow as well. So I'll add that one.