Note: All are SSBBHere we go:
Neutral-A: Mario's side tilt -> Luigi's down tilt -> Mario's down air, but Asriel does not rotate and the particles are replaced with fire (aka the Fire Helix)
Dash Attack: Pretty much a cartwheel.
Side Tilt-A: SSB4 Mewtwo's neutral-a repetitive tap
Down Tilt-A: SSB4 Mewtwo's down smash but dark energy replaced with Yoshi's down special star
Up Tilt-A: Mario's up tilt
Side Smash: Mario's side smash but replaced with electricity
Down Smash: G+W's Down Smash, but Asriel uses his Chaos Sabers.
Up Smash: Link's Up Smash with Chaos Sabers
Neutral Air: Midair cartwheel like Kirby's and Villager's Neutral Air
Forward Air: Mario's Forward Air
Back Air: Pikachu's Back Air (This will be funny
Up Air: Samus' Up Air
Down Air: Pikachu's Down Special, BUT the lightning starts at Asriel's position on the stage.
Neutral Special: Asriel rapid-fires his Chaos Buster at the direction he is facing, and can tilt the way the bullets go. He can charge it to make an Aura Sphere like Lucario or Mewtwo.
Side Special: Zelda's Side Special, with added stars.
Up Special: Toon Link's Up Special, with Chaos Sabers.
Down Special: Pikachu's down special, but this time much faster, less damaging, and will pierce through anything before it hits the stage.
Grab: Leans forward and grabs enemy.
Pummel: Asriel uses friendliness pellets to pummel the enemy.
Forward Throw: Mewtwo's Forward Throw, but replaces Shadow Balls with stars.
Back Throw: Mario's back throw.
Up Throw: Mewtwo's Up Throw.
Down Throw: Pikachu's down throw.
Neutral Taunt: Asriel flips his Chaos Buster around him like a sign flipper.
Side Taunt: Asriel holds out a flower, and then puts it in his pocket.
Down Taunt: Asriel sits down like Mr. Game and Watch, and then gets back up.
Final Smash: Asriel transforms into the Absolute God of Hyperdeath and uses the Hyper Goner Attack, which sets the health of every player who touches a bullet to 999%.