CardiganBoy
Smash Lord
I know it sounds weird, but something similar to Mii Gunner's Up Air would look amazing with Phazon shots, of course.
Considering Dark Samus AT has that multishot attack in Smash 4, Mii Gunner's Up Air would fit pretty great, imo.
(in 1:52)
For Fair maybe she points the cannon, and does a single shot, a fast attack, the shot is weak and deals extra damage if the opponent is just "in" the cannon as it shots. i don't know what to suggest for Bair other than some downwards kick.