Mega Man X4

Story
X's story: X comes to earth to find it being attacked by an unknown enemy, later X finds the Coloinel which he thinks attacked earth, which this sparks a giant fight between the Repliforce and the Maverick Hunters, as X is at the Hunter Base he meets a fellow robot named Double, Double befriends X and helps with information. As X fights each and every Repliforce Marine/Maverick the story unravels.