The Experiment is no threat until it hits its maximum level, at which it can use its powerful Annihilator ability, of which can be learned as a Blue Bullet. Having Protect up at the start of the battle helps lessen the amount of damage it can deal while carrying several Mega-Potions and focusing around using Power Break (in the European version, it is immune) and Armor Break will go a long way. It can only be fought once each time until level 5, and once the player runs out of repairing manuals, and if it is not defeated at level 5, the player will be unable to fight it at level 5.