Try to avaoid them if possible. I was wandering around Ridgeside and all of the sudden, BOOM, this gravity hole just explodes into existance right in front of my face and sucks me in. Luckily i wore my lucky boots that day and survived to have this story live on.
It looks pretty good, it's pretty obvious it's a banshee though. A different angle and having the camera zoomed in a little might help. But I still like the screenshot, definitely looks like a vortex sucking him in.
The banshee wings kind of look like arms trying to grab hmm or something but it would look better without them. The idea is really cool and it looks like you captured it fairly well. Just try to angle it a little different to "hide" the banshee.