She crushed a city using the force. Force stasis just means she holds people in place without movement. She has no neural system (she's essentially a spirit, and therefor was defeated in the "spirit world" of sorts). She can teleport at any time to hide and avoid any super weapons (which by the way would just end up wiping out other forces, and Mandalorian ore is indestructible which could be used by the Jedi and Sith for protection). And you may have a point about the black holes. And the life drain means she just sucks the life out of others. There's not really a defense against it.