A group of Androids created by Dr. Gero, a former Red Ribbon Army member, appear three years later looking for revenge against Goku. During this time, an evil artificial life form called Cell emerges and, after absorbing two of the Androids to transform into his perfect form, holds his own fighting tournament to challenge Goku and his friends. Gohan defeats Cell, when Goku dies again. Seven years later, Goku, revived for a day, and his friends must defeat Majin Boo. After a lot of battles, and after the re-creation of Earth, Goku destroys Boo with a "Genki-Dama" attack and wishes for him to be reincarnated as a good person. Ten years later, Goku meets and trains Boo's human reincarnation Oob, to have him becoming the world's protector.