Bison later appears in the Street Fighter Alpha trilogy, a prequel to the Street Fighter II series. In Street Fighter Alpha: Warriors' Dreams, Bison appears as the final boss for certain characters and a hidden playable character available via a code. Two characters with ties to Bison were introduced: Rose, a fortune teller with spiritual ties to Bison, whose Soul Power is the opposite of Bison's Psycho Power; and Charlie (Nash in Japan), Guile's deceased war buddy previously mentioned in Street Fighter II, who seeks to track him down. Bison, as he appears in the Alpha games, fights wearing a cape, and gains a teleport and a projectile move. Street Fighter Alpha 2, released the following year in 1996, follows the same plot as the original Alpha, but features completely revamped endings. Bison is featured in this game as a playable character without any cheat codes required. In Street Fighter Alpha 3, released in 1998, a powered-up version of M. Bison serves as the final boss of the game. He is the final boss for every character in the game except for Evil Ryu, whose final boss is Shin Akuma, and his final opponent is Ryu himself. Several revelations are made in this game, including the fact that Rose is the good half of Bison's soul and the fact that Cammy is a female clone of Bison. In the canonical story of Alpha 3, Bison is revealed to be dying due to the strain of Psycho Power on his body and the only thing keeping him alive is his Psycho drive, which brings him to search for Ryu, whose body he has deemed worthy of possession due to Ryu's struggles against the Dark Hadou, which Bison believes will sustain him. In the story, depicted in more than one ending, Bison fights Ryu and very nearly possesses him, but Ryu, with his memories of Rose, Akuma, Sakura, Chun-Li and Ken, is able to counter Bison's Psycho Power with his Hadou and ultimately overcomes the warlord, while Rose punches a hole in Bison's body. Before he can be destroyed, Bison transfers his soul into Rose's body, rendering her unconscious before his body disintegrates. Rose's body is recovered by Guy while Bison is presumed dead. Similar endings apply to the game's other characters.
