I like this topic.
The following Final Smash is actually for my character in the RP I do with my girlfriend, but he's based off of me. So it's okay.
<Dark Angel>
Here to fulfill the Prophecy of the Dark Angel, Kurai has obtained the smash ball!
Angel wings...but they're black!?
The shadows have immoblized you!
He grabs you! What is he doing!?
He fires several nova beams into your stomach!
Then he throws you into the air!
To finish it, he flies upward and strikes you with his sword!
Here's basically what happens. The character, Kurai Oscuro (AKA me), can control shadows. So shadows fly from him in one direction towards another player, similar to how Link's FS is activated. Then, using his enhanced speed, he flies to the player trapped in the shadows and grabs them. Kurai can fire a beam of energy known as "nova" out of his hand, and he does exactly that after grabbing. He then throws the other player high into the air, and flies into the air after them and meteor-smashes them into the ground. Visually, it would be one of the more impressive Final Smashes in the game.