He-Man

Followed Zoar to Castle Grayskull, given the Sword of Power by the Sorceress;
Gained the ability to transform into He-man, committed to use his powers for good
Fought many battles with Skeletor & his evil Warriors over the years
Gave up the power when he was tricked into believing he had killed someone;
Threw his sword into the abyss but later retrieved it after discovering the truth
Channeled all the magic from the Orb of Power, after Skeletor broke it, saving the world;
Died & went to Preternia, later returned with Teela to the land of the living
Skeletor & Evil-Lyn stole the Sword of Power, regained it & defeated them
Abolished the royal monarchy & let the people govern themselves, after his father died
Had his sword upgraded with tech & defeated the Horde when they returned to Eternia