Throm

Throm is the grotesquely worm infested Grodol king. He used to be a prosperous leader until he was infected by worms that affected him physically and mentally. He became hated by Morgrom and the other Grodol, and when Mia arrived, they asked her to kill him.

Strategy
First, you must attack his body parts (arm, legs, chin, etc) first. To do this, stand on his level, and attack continuously, or stand on the level below and use your hammer. Kneel and attack to kill the blue worms. Note that you cannot hit a body part and a worm simultaneously, so be careful. The first part's easy.

After you kill all his body parts, jump to the lower platform to a safe spot with no blue things. When he starts walking, go under him and attack his legs. His legs can't hurt you, so stay under him. This is a safe spot that the jumping worms won't be able to reach you. When his legs are destroyed, go to the right, it's easier to attack him from behind.

From behind you can shoot your charged sword, and he won't be able to hurt you. Jump on the platform where he was, and attack continuously, and be careful about the blue worms jumping at you. He's going to have a net movement of going leftwards, so attack him as much as possible. When he becomes out of range, use your charged sword.

When he leaves the screen, jump down on a safe spot (the floor will be full of blue things). When you do, attack each worm on the floor standing up (if you have all the scrolls you should have, you will have the curved sword that can reach the floor). When you get to him, jump and attack his head, until he dies.