Geno Whirl is the strongest attack in the game Super Mario RPG: Legend of the Seven Stars. If it isn't timed right, it will do just around 500 or 100 damage. However, if timed right, it will do maximum 9,999 damage. It doesn't apply to bosses and stronger enemies (mini-bosses), though, but it applies to Exor, which is a Time Level 1 attack.
The timing can be difficult to get right. You must hit any letter button exactly when the last circle goes out of the screen. If it's timed right, a thunder sound effect will play. This is hard because every circle gets more and more transparent. That means, that the first circle is seen in complete color, the second with 90% transparency etc.
When you stun the right eye or both eyes, you can use that on the top part of the sword (the part with the flashing thing). This is like this because Exor is used for a portal to the Factory. Exor himself is not a boss. Only the eyes and the mouth are a boss. The main part is a normal enemy, that can be attacked only if the right eye boss or both eye bosses are killed.
- Every time the player uses this, Geno makes his victory sign.