Close the Circuit5U
Convoke (Your creature can help cast this spell. Each creature you tap while casting this spell pays for 1 or one mana of that creature's color.)
You may cast sorcery spells this turn as though they had flash.
When you cast your next instant or sorcery spell this turn, copy that spell twice. You may choose new targets for the copies.
A one-turn mass Quicken with a flashback-ed Curse of Vengeance on your first spell is great... but this is six mana. Intresting way to show Quintorius sparking, but probably not that good in practice.