Ballade

Ballade is a major antagonist in Mega Man IV but a minor antagonist in Mega Man V and Mega Man 10

Mega Man IV
Ballade was created by Dr. Wily, as the third and last Mega Man Killer. Ballade is very arrogant and believes he is the strongest robot.After Mega Man defeat the four bosses, Mega Man invades the Wily Station and fights Ballade inside,after Mega Man defeat the second four bosses,he fights Ballade again,but more powerful,after losing by Mega Man twice, he realizes his mistakes,near the end of the game,Ballade sacrifices his life to save Mega Man by self destructing to open the way for Mega Man escape the exploding Wily Battleship

Mega Man V
Ballade returns in Mega Man V as the Fourth boss in the Wily Star,this Ballade is actually a clone.

Mega Man 10
Ballade returns in Mega Man 10 as a Super-Boss.