Nice work making waluigi a playable character!
I just wanted to contribute with a waluigi moveset i thinkered a while ago, I'm aware there's a LOT of limitations with alloy-based characters so don't take this to serioulsy, I posted this for fun and thinking that maybe you could find some inspiration in it
-Jab: 2 diagonal slaps with the right hand... think of diagonal karate chops, like manlier slaps
-Dash atk: football kick, like making a penalty shot
-Ftilt: take off his cap and swings it , great range!
-Utilt: swaps his hand twice above his head with an angry look, like getting rid of an insect
-Dtilt: crouches and makes a tripping kick with fury
-Fsmash: a grand slam with the racket
-Usmash: he crouches a little, then above his head appears a block of random tipe: mario party dice, mario kart item block, mario kart fake block, etc...(just cosmetic)..., then he smashes it
-Dsmash: crouches and moves like making the signal for "safe" that is made by baseball umpires when a runner is safe in a base
-Nair: a sex kick (like mario, luigi and wario's Nair)
-Fair: an aerial grand slam with racket
-Uair: puts his hands up then swings them down, when this hits, the other character goes below waluigi without been spiked so this can be followed by with another aerial
-Dair: waluigi whirl (mario power tennis) (like mario, luigi and wario's spinnig Dairs)
-GrabPummel: knee to stomach
-Fthrow: plunges the oponnent into the ground and hits it with a golf club (mario golf), then puts his hand on his forehead like looking where the opponent goes flying
-Bthrow: spins the oponent twice and throws it (like mario, luigi and wario's sppining throws)
-Uthrow: makes a "ball" with th opponent and throws it up in a basketball motion
-Dhrow: releases the opponent and hits it with an purple vine whip, sends it in a diagonal trajectory (purple vines come from mario soccer)
-NeutralB: sweeps his vine whipe arround him, like metaknight's jab, in air he spins it like melee kirby's hammer
-SideB: takes a ball of random tipe: football, basketball, baseball, an eggplant (mario super sluggers), a rocket (mario party), or a bom-omb (mario kart ddash), each one with different damage, knockback and travel distance, then he charges the throw the same way sonic charges his Fsmash, you can trhow grabbed items with this move also
-UpB: air swimming (mario hoops 3 on 3), great aerial movement
-DownB: i like the guard mechanic what you made, he laughs an attack
-Final: two ideas: 1) waluigi's crazy land or whatever: the stage transforms into something related to pinball, pirannah plants, purple poisonous vines, bom-ombs, etc...
2) waluigi takes a bag with 10-15 bom-ombs to fire at will !!!!!
Any thoughts??