Ganondorf

Ganondorf was the only male king born among the Gerudo. Motivated by envy of the Zonnan dynasty's power, he feigned allegiance to Hyrule's first king, Rauru. He tricked Queen Sonia into murdering him and stole her Secret Stone, a sacred artifact that exponentially amplified his dark powers and transformed him into the Demon King. He commanded hordes of monsters against Hyrule. Rauru and the Original Sages managed to corner him, but unable to destroy him, Rauru sacrificed his own body to seal Ganondorf's essence deep underground for millennia. As the ages passed, Rauru's seal weakened. Link and Zelda investigated the depths of Hyrule Castle and found Ganondorf's mummified body. Ganondorf awoke, destroyed the Master Sword, swollen Link's arm, and caused "The Shock," raising islands in the sky, spreading miasma throughout Hyrule, and unleashing chaos. He barricaded himself in the abyss of the underground to fully recover his body and energy.
In the final confrontation against Link, when he finds himself cornered and overwhelmed, he resorts to the forbidden act of Draconification: he swallows his own Secret Stone to become the Demonic Dragon, losing all his sanity in exchange for colossal power, before being definitively destroyed by the restored Master Sword.