In episode 150, Seto Kaiba was brought into the Dominion of the Beasts through a vision when he was about to lose against Alister. Kaiba then saw that he was chosen to release Critias from his 10,000 year long slumber. This was the second Legendary Dragon released. After Kaiba releases "Critias", he was brought back into reality. When Kaiba started the last turn of the duel, he drew this card which he was surprised at, but decided to use it anyway. Kaiba then summons this card (much to Alister's shock) in Attack Position. Kaiba then fuses this card with his set "Crush Card Virus" in order to Special Summon "Doom Virus Dragon".
In episode 151, Kaiba looks at this card as he and Mokuba exit Duelist Kingdom. Kaiba wonders how this card got into his Deck as he never placed it into his Deck before.
In episode 152, Kaiba looks at this card as he and Mokuba head for Industrial Illusions. Kaiba remembers his earlier Duel with Alister and notes that it's as powerful as the Egyptian Gods, but he has never heard of it before and it's not in the database either.
In episode 152, this card appears in a flashback Kaiba has when he remembers using this card in his Duel against Alister.
In episode 153, Joey ran out of options to survive his rematch with Mai, but his Deck began to glow. Kaiba then noticed his Deck glowing. He then takes the glowing card out and sees that it is this card, signifying that the third chosen Duelist has been chosen.
In episode 154, all three chosen Duelists (Yami Yugi, Kaiba, and Joey) came together in Industrial Illusions and each showed their respective Legendary Dragons. All three cards then begin to glow since the chosen Duelists have now united. They then hold their respective cards up into the air. In the next episode, the glow soon disappears and the three Duelists lower down their cards before Kaiba and Mokuba leave.
In episode 167, Kaiba uses this card during his Duel against Alister. He activates this card to merge it with "Tyrant Wing" in order to Special Summon "Tyrant Burst Dragon". After Kaiba defeated Alister, he tries to stop the plane from crashing, but it is no use. All three Legendary Dragons then came out of their owner's Decks as actual monsters. They then gathered around the plane and brought it down to the ground safely.
In episode 168, Yami Yugi and Kaiba confront Dartz at the KC USA building. They then summon their respective Legendary Dragons against Dartz and the Great Leviathan. Dartz asks Timaeus how his eye is before Timaeus lets out a roar. Timaeus attacks Dartz and the Great Leviathan, but they escape. Shortly after, both Legendary Dragons were recalled back by their masters.
In episode 170, Yami Yugi and his friends get surrounded by Orichalcos Soldiers, but Yami Yugi and Kaiba summon their Legendary Dragons and use them to defeat the many soldiers. A soldier then tries to attack Kaiba directly, but Critas crushes it down and defeats it. After the soldiers are cleared out, Yami Yugi and Kaiba recall back their Dragons.
In episode 171, Kaiba and Mokuba noticed this card glowing after Joey played his Legendary Dragon, "Hermos". After "Rocket Hermos Cannon" is destroyed, both brothers notice the glow fading out. This makes Kaiba wonder what happened to Joey.
In episode 173, an Orichalcos Soldier grabs Mokuba and holds him captive, but Kaiba summons this card and uses it to destroy the soldier, saving Mokuba. The soldiers then close in on the brothers, so Kaiba orders this card and "Blue-Eyes White Dragon" to attack the soldiers. After Joey loses to Mai, Kaiba and Mokuba notice Critias appearing physically and roaring in sorrow before flying up into the sky. Kaiba notes that Critias is crying, but doesn't understand why. This signifies that Critias has learned that Joey and Hermos have lost to the Orichalcos.
In episode 182, Yugi Muto gives this card back to Kaiba before the Chosen Duelists enter the portal that would lead them to stopping a tsunami and Dartz. Later Kaiba uses this card in the battle against The Great Leviathan. After all three Chosen Duelists summoned their Legendary Dragons, Yami Yugi uses "Legend of Heart" to transform the Dragons into the Legendary Knights.
In episode 184, Yami Yugi was able to defeat Dartz and The Great Leviathan. Once that was done, Critias returned home with his friends. This card along with the other Legendary Dragon cards dissolve away when this happens as the Legendary Knights no longer need to assist the chosen Duelists or their comrades with the Orichalcos and the Great Leviathan defeated for good. Kaiba however claimed that his deck is unbeatable even without Critias by his side.