Ben 10: Ultimate Alien Episode 1.19 Absolute Power, Part One

After Kevin absorbs the powers and abilities of Alan, Helen, Manny, Pierce, and Dr. Vicktor, Ben and Gwen argue about the best way to deal with him. Ben decides to kill him, while Gwen argues that Kevin can still be saved. The argument escalates into a heated battle between the two first-cousins, which Ben wins as Way Big using an incredibly strong and powerful cosmic ray attack. He then starts looking for Kevin, attacking anyone who has ever had any criminal connections with him, including the Forever Knights and Vulkanus. Gwen, looking for an alternative, tracks down Darkstar. She convinces Darkstar to help Kevin, and in return, she gives him enough mana to retain his normal appearance for one year. Together with a newly matured Cooper, Darkstar devises a plan to save Kevin using a fragment of the Dominus Librium. He and Cooper build a machine in Los Soledad, using the left over pieces of both Aggregor's matter energy converting device, and Professor Paradox's time machine, to strengthen and amplify the piece's energy-draining abilities, thus restoring Kevin's sanity.