Mario
Mario swung his fist and had decimated the Smash Ball. The energy surged through him as he fell back to the platform. As the others missed, they worried more about any chance of survival, even though they knew there was none.
It felt good having all this power, he started to laugh. His spam-based Special Attack "Fireball" would be an crumb compared to his Final Smash, the "Mario Finale".
He heard a God-like voice call to him. "FINISH THEM!! SHOW THEM WHAT YOU'RE MADE OF!!" He turned towards the direction of the voice and nodded. He knew it was time to end this battle once and for all.
As the other three rushed to the edge, trying to find a safe spot or an escape route, Mario sauntered up to them, his golden aura glaring aloud. He circled his arms, his hands flaring a deadly red fire, aching to fly out of his palms.
Mario took pride in these lasting seconds. The power felt best as he started his assault. "Oh yeah," he muttered. He thrust his open hands forwards, releasing the great twin dragons of hellfire. As they were released from their eternal prison, they spiraled, eating everything in their path.
"HEEEEEEEE-YYAAAAAAAAHHHHHHHHHH!!"
As Luigi saw the dragons head straight for him, he decided to take one last life-or-death risk, not wanting to be remembered as a coward by jumping off the edge. He tried to jump between them but was carried away to his doom.
Wario tried to run them over with the "Wario Chopper", but only succeeded in getting his bike destroyed and defeated. He would never let this image leave his mind.
Waluigi, going down with honor, saluted Mario as the dragons flew in his direction. He knew it was over, there was no point in trying to win here. As he was eaten and carried away, he swore he'd get his revenge after he got Luigi.
"GAME!!", and that was it, he was alone. He cried out a tear.