Make Waluigi's Final Smash be him sealing his opponents inside an Assist Trophy, removing all of their stocks at once as they are no longer playable characters

Swap Chibi Robo and Telly's role.
Telly is the one you control and beat up opponents, while Chibi follows Telly around and gives "emotional support" to Telly.

Change every character except Lloyd to a 3D model, including Game and Watch. Have them all be Brawl styled except for the anime characters who have models from Jump force.

Desprite Lloyd even more (desprite is the opposite of resprite for those who don't know).

Resprite Kirby some more to make his inhale even more disturbing.

Since Waluigi's up air spikes, make his down air sends opponents straight upwards.

And make Sonic's similar-looking up air spikes to match Waluigi's.

Give every character Waluigi’s up air, and have grow Sans legs because sansbag

Replace all of ‘s sprites with my pfp

Make ‘s final smash be f***ing the opponent to death

Replace ‘s side taunt with the entirety of all the funimation leaks

I second this

Leak all future characters through 4chan.

Make Goku’s Final Smash be applying the sacred ointment
Add King Dedede and have his Final Smash be seducing the opponent but only if they’re playing as Kirby (oh god I was just thinking that because he’s my main, I just realized what I typed )
Nerf Tails so that he’s literally just Melee Kirby
Give Waluigi the aforementioned Dedede Final smash
Bring back the old Haste from 0.9b

make hat kid dancing an assist trophy

^THIS IS FOR BAD IDEAS, NOT GOOD ONES.

Add D.Va and make this her victory screen (kinda maybe nsfw?):

_{k, sorry ;-;}
Replace Mario Finale with Time to take a piss, and make Mario shoot a super laser piss.
After that a Goomba says "WHAT THE HELL ARE YOU DOING"
Then Mario says: "I'm reusing old jokes!"

Remove Naruto's right arm from his sprite.

Make Luffy immune to electricity so Pikachu and Pichu are useless against him.