When Ike acquires a Smash Ball, he will swing his sword while invincible for a short bit. If he successfully hits someone, he will bring the victim up to the center of the top of the screen and start slashing at the trapped characters seven times before making a stronger slash downward as a finishing blow. Trapped opponents as well as nearby characters get sent away by the large explosion.
"Ike's Final Smash--a powered-up version of his signature move, Aether. Ike faces a foe and swings his sword up for a hit, then tosses his sword into the air, performs multiple nasty strikes, and finally unleashes a mighty overhand blow to send his opponent plummeting down. It's a very impressive sight, but if Ike misses with the first upward swing, he can't use the move."
Super Smash Bros. for Wii U
NTSC: "Ike's Aether up special is combined with a relentless barrage of sword blows in this powerful Final Smash. He knocks targets into the air with an upward swing, and then they're stuck there as he strikes over and over. Finally, he slams them down to the ground and launches them. Just make sure that first strike hits!"
PAL: "Ike's Aether up special is combined with a relentless barrage of sword blows in this powerful Final Smash. He knocks his target into the air with an upward swing, and then they're stuck there as he strikes again and again. Finally, he slams them down to the ground and launches them. Just make sure that first strike hits!"
The move is partially based off Ike's Aether skill in Fire Emblem: Path of Radiance and Fire Emblem: Radiant Dawn. It is also likely based off Radiant Hero, the final chapter in Radiant Dawn. Ike is surrounded by blue flames with the goddess power as he performs the final attack
Due to sending Ike to the center of the stage, this attack has the chance of causing Ike to self-destruct in stages with no center. This is only possible in custom stages in Brawl, but stages like Gaur Plain can cause this in Super Smash Bros. for Nintendo 3DS/Wii U.
Despite being Ike's Final Smash, it actually isn't his most powerful attack knockback-wise with Eruption and his forward smash both able to send opponents farther. However, it is damage-wise.