Mega Man Powered Up/Copy Robot

Boss: Copy Robot
The Copy Robot is a duplicate of whichever character you're playing as.

Copy Mega Man
Stun weapons: None (when using Mega Buster; other weapons have the corresponding stun weapons for the Robot Master)

Unlike in the original NES game, here Copy Mega Man can switch weapons independently of you, rather than being limited to using the same weapon you are. However, he takes on the weakness of the Robot Master whose weapon he's using. Pay attention to his color scheme to see whose weapon he's using, then use that Robot's Master's weakness. Unless he uses the Rolling Cutter; there aren't any blocks around to throw with the Super Arm, so just use your Mega Buster then. On Normal Mode, he'll have the Slide and charge shots, even if you don't. On Hard mode, he will only use Mega Buster charged shots.

Note: The following chart only applies if Copy Mega Man is using the Mega Buster. For the other weapons, use the exact same chart of the Robot Master whom the weapon belongs to.

Copy Mega
Stun weapons: None

Copy Roll
Stun weapons: None

Copy Roll likes to run toward you and use the double-swing, apparently unaware that your temporary invincibility will make the second swing useless. The same goes for her, so don't make the same mistake. The key here is jump swings. When she runs toward you, jump over her, turn in mid-air, and whack her from behind right before you land. The landing lets you instantly recover from the swing, so immediately run away before she can counter-attack. If she starts jumping toward you, run under her, turn, make a short jump, and strike from behind, then run away.

Copy Protoman
Stun weapons: None

Copy Robot Masters
The Copy Robot Masters fight exactly like their originals do when you fight them as someone else. The differences in the Robot Masters when they are played as do not apply to their copies, so keep that in mind. Since they're all resistant to their own weapons, you won't be able to do much damage to them per hit. Neither can they, but they can inflict collision damage on you. Note that as Time Man, your Time Slow cancels out Copy Time Man's.