Deep Sea- Lighting/Comp

Hello,
This is my first lighting piece on Katana. I just learned Katana this year (2018). I tried to recreate an underwater lighting.

I took the model on Truong CG Artist Gumroad : https://gumroad.com/truongcgartist.
He is a rigging artist, so I placed the model on the scene and posed it.

I did two versions of lighting.
You can read why on the description of the images.

If I choosed this creature, it is because of my fear of the abyss, I tried to "fight" this fear.