Hope it's not too late to sign up
My moveset idea:
His standard attacks would deal pretty average damage. Can't think of any now.
B: High-Damaging energy ball appears around him, much like Kirby's "Shock" ability, but darker and temporary. If you hold a direction for a little, it'll more that way, kind of like how you can choose where Ness' PK Flash leans.
Side B: He thrusts forward and chokes whoever is in front of him. This would be like Ganondorf's side B (but hopefully Ganon is different by then), but he throws them down. The opponent will not be helpless, but they will not be able to react for a few frames and can still react to recover. If done on the ground, this move creates an off-the-ground effect. This is a reference to the GX cutscene where Deathborn is seen choking Black Shadow.
Up B: A very slow teleport. Deathborn can be seen entering and exiting a portal upon exit and entry. Could be very predictable. The range could be very similar to Zelda/Sheiks. This is one of Deathborn's known powers, where he can teleport to whereever he pleases. This portal could lead to "hell" and back

.
Down B: A little burst of 3 small dark pillars come up from the ground and block opponents from approaching. They would deal low to medium damage, but force opponents backwards with minimal knockback. When done from the air, the pillars still appear, but smaller. There is no backwards force, but there is more knockback. The pillars may fall a tiny bit before disintegrating.
Final Smash: "Outer Limits". Like Marth's, Deathborn bursts forward and grabs multiple people. Then, a portal opens below them, and the appear in his version of Hell, where he runs over them in the Dark Schneider. This could be like Falcon's FS with a cool, flashy, F-Zero-esque cutscene.