Dr. Wily is the antagonist of the main series Mega Man games. Formerly a colleague of Mega Man's creator Dr. Light, the two had a falling out, resulting in Dr. Wily reprogramming six of Dr. Light's robots, which Mega Man eventually fought. Since then, he has created his own robots and built many fortresses, where he acts as the final boss. As a running gag throughout the classic series, Dr. Wily always ends up on his knees and begs Mega Man for mercy after he is defeated, although most of the time he still escapes. His creation of Zero and the virus within him also makes Dr. Wily indirectly responsible for the events of the Mega Man X series.
Dr. Wily's first appearance inside the Wily Capsule was in Mega Man 4, and since then, it has been part of his final battle in all main series games (with the exception of Mega Man 11), using different designs and attack patterns. The Wily Capsule he uses for his Assist Trophy role in Super Smash Bros. Ultimate is specifically the one from Mega Man 7. Much like in Ultimate, he attacks by teleporting to random spots in the stage and firing four elemental orbs, which spread around Mega Man before flying towards him, as well as launching electricity downward that spreads across the ground. Unlike in Ultimate, he does not have a spinning ram attack. The elemental orbs can use fire, electricity, or ice; while electric orbs merely damage Mega Man, fire orbs cause him to temporarily burn in place and take constant damage, and ice orbs freeze him. The Wily Capsule in Mega Man 7 is notably one of the most difficult bosses in the Mega Man series, as it is only vulnerable to a few weapons, all of which deal minimal damage, while its elemental orbs deal high damage to Mega Man and are very hard to dodge.
Dr. Wily appears as a trophy in both versions of the game.
As an Assist Trophy
Dr. Wily appears as an Assist Trophy in the form of the Wily Capsule (ワイリーカプセル, Wily Capsule), specifically the form present in Mega Man 7. When summoned, he teleports to random spots above the stage and spreads four orbs around himself, which track opponents' movements before flying towards them. Each orb randomly uses one of three elements, from fire, electricity and ice, with the latter two paralyzing and freezing opponents respectively. Dr. Wily also fires electricity towards the ground, which splits into four orbs that travel alongside it, and rams into opponents while spinning, dealing high damage and knockback. If the Wily Capsule is destroyed, Dr. Wily falls to the ground and begs for forgiveness. Dr. Wily can't appear in Mementos and King of Fighters Stadium