Complex sentence: The first Slann spawned in the world and the most powerful wizard in the game; his corpse is carried into battle, but his soul does all the fighting and is helped by the trusty mummified skink attendant that helps him fight once he gets into close combat.
Split into simpler sentences: The first Slann spawned in the world and the most powerful wizard in the game. His corpse is carried into battle, but his soul does the fighting, and is helped by his loyal mummified skink attendant that helps him fight in close combat.