I will give Grindelwald credit where it is due. Protego Diabolica is a useful spell not just in protecting the distance between combatants but also for locking them in and preventing flanking or escaping. While the black cursed flames aren’t nearly as potent as hellfire or fiendfyre they will certainly eat through anything living and only grow stronger as they feast on the life force of those deemed enemies, with enough death they could eventually rival the destructive power of fiendfyre without the nasty habit of it running out of control. Of course I