Doku and his cohorts reactivate an ancient tower that the Wizards of Yan built after the war with the Ethos - with the help of Adam - enabling it to fly. Meanwhile, Seth is having a hard time adjusting with his rock for a hand. He and Mel try a Wizard technique to restore his hand but not success. Just then, the Dojo's detection systems discover the tower and Mel, Erik and Rion leave to stop it. However, against the other's recommendations that he stay, Seth tries on a mech arm that Erik was designing for him but didn't get the Infimatter stabilized, giving him a darker outlook. Later, the Defenders reached the Castle, on its way to Arboth. Doku detects their approach and arms the tower's defenses. Then Seth, who just came in, was tractored by Adam and taken prisoner. Doku then betrays Adam, revealing that he had been copying the tower's codes then will drain Arboth's di-gata energy, allowing him to restore his lost eye and right arm. Seth, corrupted by his prosthetic, decides to go along. Adam, realizing that the power drain will destroy Arboth forever, tries to dissuade Seth, but Seth states that he didn't owe Rados anything. Adam is furious, and yells at Seth, saying he is not fit to be a Defender, let alone their leader. Doku manages to restore his flesh and as Seth begin his restoration, Brackus breaks in, overpowering the former Lords of Infinis. Outside, Erik comes up with a plan to stop the tower - by sacrificing their guardians. While they succeed, despite Rion and Adam's initial doubts, Seth realizes what he done just to save his hand. He reverses the tower's polarity, returning his hand to rock and the energy to Arboth, as well as the other's guardians. Using his rock, Seth sabotages the towers systems and passes out. Brackus then saves him just as the tower comes crashing down. Seth admitted what wrong he had and quits the Di-Gata Defenders. Saying "I'm not fit to be a Defender".