He is much more often called “Monster of the blue sink holes” but Lusca is shorter so we ball. Luca is another nickname.
He is kraken-like in appearance, deemed a "monster" heart. He doesn't hold a card.
He was Banished/"Killed" by Erzu in her youth—her sword to his heart; yet recently came back resentful via an unknown deal offered to Sabado(?).
Before his initial banishment, he would often leave curses on siren and pirates, the easiest being increasing the weight of ships or sending sirens into a monster-like, mind-fried frenzy. If not cursing them, or toying with them, he eats them.
He is deemed the ruler of the blue sink holes, and most who lose their way into the sink holes will be eaten by him if a smaller lwa doesnt get to them first.