Complex sentence: Helmut then releases his father's army to face the rebels and tries to kill Jimmy, however by killing Gorilla-Man, Helmut gets cursed and is turned into the new Gorilla-Man.
Split into simpler sentences: Helmut then releases his father's army to face the rebels and tries to kill Jimmy. As a side-effect of killing Gorilla-Man, Helmut gets cursed and is turned into the new Gorilla-Man.