Maximillion Pegasus created 3 Duel Monsters cards, who were known as the Wicked Gods, to keep his Egyptian Gods in check, but stopped their production due to his fear of their immense power. After Pegasus passed away, Yako Tenma completed what Pegasus had left behind of the three Wicked Gods.
Yako planned on linking Anzu Mazaki to the 3 Wicked Gods as well as use "The Wicked Avatar" as a medium, in order to revive Pegasus.
Once Yako touched "The Wicked Avatar", it possessed him, damaging his mind, giving him a need for revenge. He used this card in his Duel against Seto Kaiba, defeating his strongest monster. When Kaiba Summoned a monster with high DEF, he also Summoned "The Wicked Dreadroot", winning him the Duel.
Due to the Summoning of "The Wicked Dreadroot" and "Avatar", Yako was able to revive Pegasus, though it ultimately failed thanks to Kaiba.
Yako used this card against Dark Yugi, causing Yugi much trouble during the Duel. Yugi's first attempt to defeat the Wicked God was to use "Union Attack", though it failed. Yugi eventually defeated the Wicked God in a Double KO with an enhanced "Obelisk The Progenitor". After the destruction of the Wicked God, Yako was freed from its influence, and Anzu was free. After the Duel, Yako tore up "The Wicked Avatar"