I had an idea of character-specific assists being a thing a long time ago, and since there's probably no other thread willing to host this topic, I created a list of each original character's possible assists, like the obsessive-compulsive freaks I am.
Mario - Cappy could split off from the main man and immobilize opponents by "capturing" them, rendering them vulnerable.
Donkey Kong - Cranky Kong could latch onto the ape's back and start swinging his mangy cane around at anyone who dare not listen to his rambling.
Link - Ravio could assist Link by attacking opponents with the rental weapons from his origin game.
Samus - Samus could summon a Demolition Trooper to shoot down the player in lead.
Yoshi - Yoshi summons the Fuzzies from that infamous level to inflict hefty paralysis upon Yoshi's enemies.
Kirby - Kirby could mound Rick to gain a nifty fire-spitting attack and one heckuva knockback decrease from attacks.
Fox - ROB 64 is summoned, with the Great Fox in tow, and unleashes laser-related havoc of Fox's opponents.
Pikachu - Butterfree is summoned, using Fly to pick up Pikachu and carry him around the battlegrounds, while Pikachu shoots Volt Balls at opponents.
Luigi - Melody Pianissima is summoned, using her jaunty haunts of tunes to create a "Negative Zone" of sorts...
Ness - Paula is summoned, creating a rainbow-colored aura around Ness to restore his health considerably.
Capt. Falcon - Samurai Goroh is summoned, acting the same as his Assist Trophy.
Jigglypuff - Mr. Mime is summoned, using Barrier to surround Jigglypuff in a forcefield, protecting it from damage for short spurts of times.
Well, that's it. I might create some more for the Melee team when Ultimate drops.
Time to bump this thread. I'm a man of my word, after all...
Princess Peach/Daisy: A swarm of
Chuckyas would appear, tossing players every which~way.
Bowser: Blue Bowser could drop from the sky, acting similar to Bowser's boss fight in
Super Mario Bros. (1985)
Good Doctor: Viruses could spawn before latching on to the opposition, dealing poison damage all the while.
Zelda/Sheik: Impa could appear, keeping opposition away from Zelda via multiple sword slashes.
Ganondorf: Like Likes could appear in swarms, leeching players of their health ala Melee's adventure mode.
Yink: Young Link could mount
Epona, allowing increased speed and (for lack of a better word...) horsepower!
Falco: Slippy &
Peppy could descend in their Arwings, before opening fire on the other players.
Mewtwo: Mew could appear in its protective bubble whilst performing
Metronome which could lead to multiple different combinations of attacks.
Pichu: Probably the same as Pikachu's...
Ice Climbers: The
Condor could descend from the sky, dropping vegetables and health items only the Ice Climbers can consume.
Marth: Sigurd could appear before unleashing a barrage of sword slashes onto the players.
Roy: Lyn appears, acting similar in function to her Assist Trophy.
Mr. Game & Watch: Snoopy Ambigious Tennis Dog with no Corporate Affiliation could appear, barraging players with tennis balls before disappearing.