High Priest of Darkness Akhenaden

" Run, Pharaoh, RUN! Follow MY rules of fate...into the void of shadows! "

The High Priest of Darkness is Akhenaden's dark side, formed when he formed a pact with Zorc Necrophades. He is an arch-enemy to the Pharaoh and one of the final antoagonists in Yu-Gi-Oh!.

Origin
Thousands of years ago, Akhenaden grew jealous of his nephew the Pharaoh, believing that his own son Seto was more deserving. He then set about stealing the Millennium Items from the Pharaoh and his priests and used them to summon the dark god Zorc Necrophades.

Zorc Necrophades bestowed upon Akhenaden a portion of his being, creating the High Priest of Darkness. The High Priest set about storming the kingdom. He summoned a legion of undead soldiers to fight the Pharaoh's army, then slipped away with Seto while the Pharaoh fought the dark god.

The High Priest killed the human host of the Blue-Eyes White Dragon and told Seto to use its power to take the kingdom for himself. When Seto refused, the High Priest killed Akhenaden so his spirit could possess Seto. He then challenged the Pharaoh to a duel, using the Blue-Eyes White Dragon against the Pharaoh's own Black Magician. The Pharaoh pulled a last-ditch effort against the High Priest by sealing both of their souls within the Millennium pendant and shattering it.

Present Day
In the present day, Yugi Muto would be the first to reassemble the Millennium pendant, becomig the host to the Pharaoh, while unknowingly reawakening the High Priest, who quietly planned his rematch with the Pharaoh. When Dark Bakura sealed a portion of himself into the pendant, the two formed an alliance.

The Millennium World
After Dark Yugi retrieved the three Egyptian God Cards and presented them to the stone tablet that documented his past life, he was sent into the World of Memories to live out his previous life as Pharaoh. While contesting with Bakura, King of Thieves, he failed to notice that the high priest Akhenaden had earlier encountered Bakura, who revealed that he knew the grisly origins of the Millennium Items. After attacking Akhenaden, Bakura escapes.

Akhenaden was visited by the now-mummified High Priest of Darkness. After the High Priest reveals his plans to his past self, he appears before the Pharaoh and his friends. The High Priest reveals himself to be Zorc Necrophades. Zorc uses his ability to turn back time to undo the Pharaoh's last attack on Bakura, allowing him to strike back and steal the Pharaoh's Millennium Puzzle.

When the Pharaoh and his priests managed to kill the Egyptian Bakura, the High Priest part of Zorc possessed Akhenaden and summoned Zorc Necrophades, who restored the High Priest to his former glory. The High Priest once again sets about once again claiming the Blue-Eyes White Dragon and possessing Seto. This time however, the Blue-Eyes White Dragon turns on the High Priest and purges him from Seto's soul.