I would love PT to make up for his absence in the roster (due to the Pokemon trio splitting ways).
But I'm not sure that's gonna happen.
But if it IS possible, I hope his moveset was all about weak Pokeball pokemon. Like a brief Torchic attack, a brief Piplup, a Mucnhlax barrier to eat projectiles, etc. All about brief Pokemon attacks.
These are my suggestions:
4 Pokemon for his specials.
-B: (Torchik using Flamethrower) [Cloned from Charizard]
-B+Tilt: (Chikorita using 3 quick razor leaves) [Cloned from Ivysaur]
-B+up: (Piplup using Waterfall) [Cloned from Squirtle]
-B+down: (Bellossom inducing sleep) [Cloned from Jigglypuff's sing]
1 Pokemon for grab.
(Gulpin) [Could be cloned from Wario's bite]
and 1 Pokemon for smash attacks.
(Meowth using scratch attacks) [Attacks could be cloned from Wolf]
(In total, 6 Pokemon. See? Red can still play by the rules!)
In fact, Meowth could take care of all the non-special, and non-grab attacks.