This is a really cool looking character

The pose is really interesting and I'm enjoying the perspective!
I think a big issue you're having here is with colours and contrast. The gloved hand is getting pretty lost in the dark pants and the hair feels like it needs some shading compared to the rest of the drawing.
I'd put a little more time into the hair to really sell the feeling of it floating, take a look at some shots of people with long hair underwater for inspiration. The strands you've got here are all really thin, it doesn't feel like it's clumping together in the way that hair does.
And last thing I'm not sure what those white shapes at the tip of the cape are but they're not reading like anything to me.
Overall I think with a bit more time for a detailed cleanup pass this will turn out great