Why does Bass fight Wily so much?
So he can be a player character. Actually in every game where it has happened there has always been a plot reason. For example in Mega Man & Bass he actually doesn’t know at first that King is Wily’s robot, so he thinks he’s fighting for Wily—but when he finds out the truth, he blows up Wily’s machines in anger at being deceived. Usually, the reason has something to do with Wily annoying Bass in some way.