Editing Slifer the Sky Dragon (section)

== Biography ==

=== Ancient Egypt ===
Slifer, alongside Obelisk the Tormentor and The Winged Dragon of Ra, is one of the three Egyptian Gods summoned exclusively by the chosen Pharaoh, Atem. When Thief [[Bakura Ryou|Bakura]] fled the palace after attacking Aknadin, Atem pursued him on horseback. To protect civilians from Diabound’s attacks, Atem allowed Slifer to take a hit, forcing the battle into the sky. However, Diabound used the darkness to ambush Slifer. Atem feigned surrender, distracting Bakura while Slifer launched a sneak attack, but Bakura countered by having Diabound execute a similar ambush. Aknadin later destroyed Slifer’s stone tablet, transferring its powers to Diabound, including Slifer's "Thunder Force" attack.

=== Battle City ===
Millennia later, [[Maximillion Pegasus]] created Duel Monsters cards representing the Egyptian Gods. Unbeknownst to him, the gods' souls imbued the cards, making them immensely powerful. Realizing the danger, Pegasus attempted to destroy the cards but ultimately entrusted the Egyptian Supreme Council of Antiquities to seal them in the Valley of the Kings. Rare Hunters managed to steal the "Slifer the Sky Dragon" and "[[The Winged Dragon of Ra]]" cards, while "[[Obelisk the Tormentor]]" was safeguarded and later entrusted to [[Seto Kaiba]].

[[Marik Ishtar]], leader of the Rare Hunters, wielded "Slifer" and "Ra" during the Battle City tournament. Using Strings as his puppet, he Dueled Yami Yugi in the preliminaries. Yugi defeated him and claimed "Slifer" as his prize. Yugi later used Slifer against Yami Bakura and again in the semi-finals against Kaiba, where Slifer and Obelisk clashed, resulting in mutual destruction. In the finals, Slifer faced [[Yami Marik]] but was destroyed by "Egyptian God Phoenix." Yugi later revived it to protect Obelisk during the duel.

=== Project R.A. ===
During Yako Tenma’s first Duel against Yami Yugi, Yugi summoned "Slifer the Sky Dragon" by sacrificing his "Magna Warriors." Despite the formidable presence of the Egyptian God, Yako remained unfazed and countered by summoning his own "God card," "The Wicked Avatar." Initially appearing as a black orb, "[[The Wicked Avatar]]" transformed into a mirror image of "Slifer."

Yugi attempted to use "Slifer's" second mouth effect to destroy "Avatar," but the attack failed due to "The Wicked Avatar's" placement on the Divine Hierarchy, which granted it superiority over "Slifer." "Avatar" then obliterated "Slifer" in a single attack, later revealed to be a result of its unique ability to take on the highest ATK on the field plus one, ensuring its dominance.

While often associated with the other Egyptian Gods, "Slifer" had only one additional appearance during Project R.A. It was briefly summoned to effortlessly defeat Cedar Mill as Yamo Yugi and Gekko Tenma ascended to the top of the Kaiba Corporation building.

=== Doma Arc ===
To regain his memories, Yami Yugi presented the Egyptian God cards at the museum’s stone tablet, but [[Dartz]] drained their power, using them to summon [[the Great Leviathan]]. After defeating Dartz, Yugi reclaimed the weakened God cards and summoned them to aid in the battle against the Leviathan, ultimately sealing its defeat.

=== Pyramid of Light ===
In a duel against Yami Yugi, Kaiba used the "Pyramid of Light" card to banish the Egyptian Gods temporarily.

=== Memory World Arc ===
In the Memory World, Pharaoh Atem relived his battle against Thief Bakura, summoning Slifer once again. Later, during the final battle with Zorc Necrophades, the gods were turned to stone. Upon relearning his true name, Atem summoned them from [[Yugi Muto|Yugi's]] deck, combining them into the Creator God of Light, [[Horakhty the Creator God of Light|Horakhty]], to vanquish Zorc.

=== Ceremonial Duel ===
In the final Ceremonial Duel, Atem used Slifer and the other Egyptian Gods against Yugi but was ultimately defeated, allowing Atem to pass into the afterlife.

=== Altered Timeline ===
In an alternate timeline, [[Jaden Yuki]] Dueled Yugi Muto. Near the Duel’s climax, Yugi transformed into Yami Yugi and summoned Slifer the Sky Dragon, declaring Jaden worthy of facing a god.