First Appearance

Guardians for Sale

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Si'i is a shady man with a Spanish accent, who can create mutant guardians with his Guardianizer.

He was, long ago, ordered by Brackus to "create the ultimate Guardian" that could be used to defeat the Defenders, but never got around to giving him one.


Born to a poor farming family in Infinor, the young Si’i immediately showed a talent for manipulating sigil energy and carving stone. It was not long before a travelling stone carver named Sari took note of his ability and adopted him into her cell. Travelling to Callisto, he learned much of the techniques of sigil bonding, and was immediately inducted into the Carver Guild as an apprentice class Yan. He took to his studies very seriously and spent many long nights studying in the carving hall and in the sepulcher. Before long his interests started to drift to guardian manipulation, a sigil art studied in theory but banned in practice. This garnered him little praise and only succeeded in suspensions and summary punishment. 

On the day of his graduation to full carver status, Si’i was denied the honourary status of Sigil Bearer, an award given to the most promising student. Storming out of the sepulcher, he swore revenge on all of Callisto. Racing to the Sigil Vault, he gained access to forbidden guardian stones and immediately set to work on splicing together an Ultra Guardian. He worked into the night to create his masterpiece and by midnight he held in his hand a stone that contained the most powerful sigil energy of five guardians. At the stone bonding ceremony he confronted his classmates and cast out his guardian who immediately attacked anyone within reach. The monstrous creature ran amok, completely out of his control, destroying the sepulcher and demolishing the entire apprentice complex before being subdued by Aron, who happened to be visiting Brim. When the battle was over and the ultra guardian encased in it’s stone, half of Callisto was in ruins and Si’i was nowhere to be seen.


When the Defenders came months later to shut down his operation, Si'i merged their Guardians into one mutant being that went after Brackus to destroy him. With Erik's technical expertise, and Si'i's knowledge of the Guardianizer, they were able to break apart their guardians and restore them to normal. Si'i was then locked in Gata-Shin prison, for illegal dealing of Guardians and endangering the lives of the Defenders.

After some time in the prison, he began to seek a more peaceful existence, free from crime and illegal trade; until the Zads broke him out of prison. Malco then demanded to know how to create a guardian out of a person, using the same Guardianizer technology he created. Scarefully, he tells Malco that he require three different Plasma Stones, ordered in certain fashion. With this knowledge Malco orders the Zad to kill him. The Defenders manage to save him and Si'i saves Erik from the Black Tar, gaining the trust of the Defenders.

Becoming a GuardianEdit


Si'i as a Guardian.

He later helps Erik dismantle the new Guardianizer to reverse its effects against Rion, by rearranging the Plasma Stones (they needed to dismantle it because they wouldn't budge), which succeeds, but costs him his humanity. He ends up falling into a lava pit with the Guardianizer, which warped his physical being, turning him into a mutated Guardian himself. He then flies away.

He has become the interest of Lady K'tahsh, as she believes his morphed state would be of help to the Ethos cause. She has tracked him to a tribal village, and had kidnapped Melosa to flush him out and sacrifice her. However, he goes berserk in the village and drains the energy of the tribe's leader, and eventually kills Kali. K'tahsh manages to capture him and sent him on his first task, retrieve the Orb of Ogama-Yan.

But soon, Si'i grew very hard to control and once broke free from the Ethos' control until he was captured again. But he still grew rebellious, so the Ethos had to personally come out and subdue him. At the end, Rion uses the ancient guardian language to communicate with Si'i, who attacks the last Ethos but is turned back to his human form.