Day 6: Monkfish
Slighted by the gods as his abyssal deep sea life was ruined as his land was raised to the surface to make a new island to appease the humans. As the lower pressures and lack of water killed everyone and everything he ever knew, he cursed the gods calling them cowards and fools.
Hearing this of course, the smug gods basically said “Prove it†and gave him magical armor to keep him alive on the surface. “For every island you conquer, it will sink back into the sea. You will fail, endling.â€
And now he wages war on the surface, trying to reclaim his ancestral home.