Top left, not a big fan of it. The lines of light... kind of give a vibe of unevenness sorta. Idk, something about that I'm not sure about. Also.. the background thingie, the dark blue... yeah no, it leaves a sense of... can't quite put my finger on it. Just that entire side seems strange, look at Angela's banners, you'll see. Also, using splatter/bubbles thing? Yeah no. Light use is good in the middle near Kai's head but it's overdone, it's too bright, spoiling the render. I also don't like the way it fades into the bottom of the background. Though yeah, extreme right is the best in the banner. So yeah. :3
Also this is basic complaints, to improve it, I'd tl;dr a lot more.. XD; Sorry, juuust saying.