#5: Metroid: Just like a tick, he sticks to you, takes away your life, and is hard to get off. Can rack up some major damage!
#4: Barbara: Though the range can be a little short if you get stuck inside her Guitar's range, you will, more then likily, stuck inside and take a decent about of damage.
#3: Andross: Though this guy is in the backround, he shoots tile like objects! They usually have good range, scattered across the stage, in huge groups in 3 waves. 
#2: Knuckle Joe: This beast from Kirby has increible attack power as long as he can keep you in. Though he can die (going off the edge), his uppercut can actually kill from 0%.
#1: Resetti (xD Nah) Saki Amamiya: This has to be the best. Just like ZSS, has a Gun that can act like a whip/sword. Able to jump good height, hover and shot. This guy can really take control of the game.