Mega Man Powered Up/Elec Man

Boss: Elec Man
Stun weapons: Mega Buster (charged), Oil Slider, Proto Strike

Mega Man: Elec Man will run across the room, shooting his Thunder Beam at you. On Easy he'll shoot it when he's only on the ground, but on other difficulties he'll also shoot it in midair. Elec Man's weakness is Oil Slider, but be careful when using it, because Elec Man may damage you by contact if you're not careful. Remember that you can hołd left on your D-Pad to slow your slider down. His critical attack causes lightning to strike directly at your spot, so move away as quickly as possible.

Time Man: Thunder Beam is Time Man's weakness, so you need to be very careful when fighting Elec Man as him. You need to run from side to side of the arena between his attacks. His critical attack shouldn't be a problem too.