There's a difference between angel and fallen angel. It's like light and darkness. Angels are supposed to be good spirits to protect the weak creatures from danger while the fallen angels are known to destroy everything they want to.

But when at a big angel gathering celebrates in heaven by Heaven God. Most of the angels attend there. And Sultan is there as well, of course. As a son of the Heaven God. And there's also Blast at the party, since he is also the son of Heaven God, except he's just being a fallen angel.