Stop is an alchemy formula. It is learned from an alchemist beneath the Chessboard, in an area unlocked after reaching Ruffleberg's Lab in Omnitopia. The alchemist only gives the player Stop if they have the Oracle Bone.
Stop paralyzes an enemy for 8 seconds, during which time they cannot be attacked or have alchemy cast on them. Levelling up Stop does nothing.
Stop is of little use normally, primarily because the player cannot damage the stunned enemy for its duration. However, it is of some use in the final battle, where multiple enemies spawn at once and Stop lets the player take an enemy out of the fight for a time to focus on other enemies.
Acid Rain - Atlas - Barrier - Call Up - Corrosion - Crush - Cure - Defend - Double Drain - Drain - Energize - Escape - Explosion - Fireball - Fire Power - Flash - Hard Ball - Heal - Lance - Laser - Levitate - Lightning Storm - Miracle Cure - Nitro - One Up - Reflect - Regrowth - Revealer - Revive - Slow Burn - Speed - Sting - Stop - Super Heal