Cyrus grew up in Sunyshore City as a gifted but asocial student who preferred machines to people and Pokémon, and came to believe that emotion was the root of all conflict. As boss of Team Galactic he captures the three lake guardians, then uses the Red Chain at the Spear Pillar to summon Dialga in Diamond or Palkia in Pearl, meaning to destroy the universe and rebuild it with himself as its god.
The player first sees him on Mount Coronet, beats him in his office at Team Galactic HQ, where he hands over a Master Ball he says he no longer needs, and fights him again at the Spear Pillar once the lake guardians shatter the chain. His teams lean on Dark and Flying types: Murkrow, Golbat and Sneasel at HQ, then Honchkrow, Gyarados, Crobat and Weavile at the Spear Pillar.
Pokémon Platinum makes plain that he wants a new world only for himself. He summons both Dialga and Palkia, is dragged into the Distortion World by Giratina, and stays there after his last battle with the player. An alternate-universe Cyrus returns in Ultra Sun and Ultra Moon as part of Team Rainbow Rocket.
His first two Supporter cards, both Uncommons illustrated by Ken Sugimori, came out in 2009. Cyrus's Conspiracy (Platinum) searches the deck for a Supporter, a basic Energy and a Team Galactic's Invention Trainer. Cyrus's Initiative (Supreme Victors) flips two coins and, for each heads, sends a card from the opponent's hand to the bottom of their deck. Ultra Prism (2018) added Cyrus ◇, a Prism Star Supporter by Masakazu Fukuda that is played with a Water or Metal Pokémon active and makes the opponent keep only two Benched Pokémon, shuffling the rest into their deck.
His first card, an Uncommon Supporter illustrated by Ken Sugimori.
A hand-disruption Supporter from later in 2009, also by Sugimori.
To destroy the universe and remake it as a world without spirit, with himself as its god, using the Red Chain to control Dialga and Palkia.
In Diamond and Pearl, Murkrow, Golbat and Sneasel at Team Galactic HQ, then Honchkrow, Gyarados, Crobat and Weavile at the Spear Pillar.
Cyrus's Conspiracy in Platinum and Cyrus's Initiative in Supreme Victors, both from 2009, and the Prism Star Supporter Cyrus ◇ in Ultra Prism (2018).

VILLAIN
2 Trainer cards · 0 partner Pokémon
Cyrus is the boss of Team Galactic and the main villain of Pokémon Diamond, Pearl and Platinum, a man who wants to erase spirit from the world and remake it with Dialga and Palkia. His first Supporter cards arrived in 2009, and a Prism Star Supporter followed in 2018.
No published index yet — too few of Cyrus’s cards trade often enough to strike one.