Galactus is the final boss of the Marvel vs. Capcom 3 style of M.U.G.E.N Trilogy. He is located at the tenth and final stage of Arcade Mode. Jonathan Adams provides the role for Galactus in this fighting game.
Galactus is the sole survivor of the universe that existed prior to the current universe. Originally Galactus was a humanoid named Galan, who was born on the planet Taa, a paradise-like world whose civilization is said to have been the most advanced of any of the known universe of that time.
At the moment Galan's universe met its end, the Phoenix Force amassed the positive emotions of all living beings in the cosmos to preserve them from eternal damnation, enabling the Sentience of the Universe — the previous universe's equivalent to Eternity — to meet with Galan. Within the "Cosmic Egg" the Sentience of the Universe revealed itself to Galan and informed him that though they both would die in the final moments of the universe, they would both survive through a joint heir born into the next universe. The Sentience of the Universe merged itself with the mortal Galan and thus Galactus, the devourer of worlds, was conceived.
Phase 1: Before fighting Galactus, the player must fight the cosmic avatar versions of either Bowser, King K. Rool, Ganondorf, Ridley, Mewtwo, Doctor Doom, Dormammu, Ultron, Wesker, Akuma, Naraku and Utsuho Reiuji. During the start of this match, the player must fight one of them for now. There is no statistical differences between the cosmic avatars versus their regular forms, minus a separate health bar and the cosmic character cannot summon other characters. After 10 seconds of the fight, another of those random twelve fighters will jump in, causing the player to face them both at the same time; the player character will always face the first avatar if both avatars are shown in different sides. Fortunately, the avatars share the same health bar, so should the player have a multiple-hitting move that does NOT target one character, the player will drain the life bar twice as fast. Once it empties, both avatars are defeated. Even though some say it would be ideal to just wait for the second avatar to come in, it may also NOT be recommended because of back attacks. Note that until the second fighter jumps in, the player cannot defeat the first; even if you completely drain the health bar, the first fighter will not be K.O.ed and will continue to fight the player. Should the player manage to do this, however, both fighters will instantly be K.O.ed as soon as the second one jumps in.
Phase 2: After besting the 2 avatars, Galactus appears, after watching the battle from a distance, and his health bar has shown to be the size of three health bars (the same as the sub bosses). Also, the timer does not reset, making this battle rather difficult when it comes to having enough time.