I just started a session with Susanoo/Ramiel and so far it's not bad at all. I'm holding off to see what I get from the second jewel gacha and SR ticket, and I'm finicky so I might drop her if I get garbage from it. But she's not bad at all, her first skill is a room cleaner by itself.
One weird thing though is that her weapon is lightning but her element is Dark, which makes building around her very specific.