Mega Man X (Marvel vs. Capcom series)

Mega Man X is a is a playable character that made his appearance in Marvel vs. Capcom: Infinite. Though he made his technical debut in Marvel vs. Capcom 3: Fate of Two Worlds, but only as downloadable costumes for Zero and Frank West and as a card in the Heroes and Heralds Mode. Though his moveset and voice did not change, X did share some of Zero's abilities and weapons during a few points throughout the series, namely his Z-Saber.

Marvel vs. Capcom 3: Fate of Two Worlds
Mega Man X made an appreance as a card in the Heroes and Heralds Mode. He was later confirmed to appear as downloadable costumes for both Zero and and Frank West and was released on February 7, 2012.

Marvel vs. Capcom: Infinite
Mega Man X, along with Strider, Captain Marvel, Gamora, Nova & Rocket head to Knowmoon to retrieve the Power Stone from Grandmaster Meio. While looking for it, X witnesses Zero being mind-controlled by Meio and is forced to fight him. X wins the fight and Zero regains his consciousness and allies himself with the rest of the heroes from then on while Strider and Gamora deliver the finishing blow on Meio. X's arm cannon design was used by Iron Man to try and create the Infinity Buster to take down Ultron Sigma. X goes with a number of other heroes back to Xgard to keep Ultron Sigma busy while Iron Man and Thanos finish making the Infinity Buster. When Thor is freed from mind control due to the Soul Stone, he and X team up to weaken Ultron Omega, alongside Captain Marvel and Dante. Iron Man then arrives to summon the Infinity Buster. X is unable to hold the strength of the buster even when powered up, however with the assistance of Doctor Strange and Morrigan, X was able to be strong enough to fire the Infinity Buster and destroy Ultron Omega, ending the monstrous dictator's rule.

Character Select

 * "Starting the mission! Let's go!"
 * "Roger! Reporting for duty!"
 * "Let's fight together, Zero." (Character Select with Zero)
 * "Hands off the buster, got it?" (Character Select with Rocket Raccoon)

Intro

 * "I'd rather not fight such valued heroes." (VS. Avengers)
 * "Let's do this Zero. Together no one can stop us!" (Zero as teammate)
 * "Watch my back, Zero!" (Zero as teammate)
 * "I've always wanted to see a real Shoryuken!" (Ryu as teammate)
 * "After this, let's work with the doc on some upgrades!" (Iron Man as teammate)
 * "Show me what it means to fight for galactic peace!" (Guardian of the Galaxy as teammate)
 * "I told you I can't lend you my buster!" (Rocket Raccoon as teammate)
 * "You can take center stage, Spider-Man." (Spider-Man as teammate)
 * "Thor, let's save both of our homelands!" (Thor as teammate)
 * "Your technology could do so much good." (Thanos as teammate)
 * "For a temporary alliance, this isn't bad." (Villain as teammate)
 * "Even if the enemy is a god, I must complete my mission!" (VS. Thor)
 * "The galaxy needs more than raw strength!" (VS. Nova or Guardian of the Galaxy)
 * "Zero!? Who's controlling you this time?" (VS. Zero)
 * "Some kind of new Maverick? It's going down!" (VS. Ultron or Dormammu)
 * "We're not the same as humans, but we can co-exist with them!" (VS. Ultron)
 * "As long as I stand, there's hope! I will defeat you! (VS. Sigma)
 * Sigma! I'll shatter your plans as I smash your body!" (VS. Ultron Sigma)
 * "Corrupted by the Sigma virus... That's where I come in!" (VS. Ultron Omega)

Victory Text

 * "Zero, I hoped it would never come to this. We should be fighting together as Maverick Hunters!" (to Zero)
 * "I can't claim to protect the whole galaxy... but anything in range of my buster can consider itself guarded!" (to a Guardian of the Galaxy)
 * "That fire I felt from your fists... So your weapons need an emergency cooldown too?" (to Ryu or Chun-Li)
 * "I appreciate what that shield means to you. Now you know what this buster means to my enemies" (to Captain America)
 * "Your past is yours alone. I've lost people along the way too, but we have a duty to keep fighting" (to Captain Marvel)
 * "You've lost. Discard your weapons. ...I wish our worlds could have met without this violence."
 * "You may not be a Maverick, but that doesn't mean I won't take you down!"
 * Whatever you scheme, I'll always be there to stop you! However many times it takes!" (to Sigma)

Trivia

 * One of X's taunt quotes is a reference to Zero's infamous quote from Mega Man X4.