Annihilation is available to any of the classes in the Ninja Class series at Level 31, meaning anyone but Mia and Piers can use it. It is aligned with the Venus element, costs 18 PP to perform, and hits a single target. It works in a manner similar to the Quick Strike technique; rather than having a base power, it multiplies the caster's Attack stat by 1.5. It is also similar to the Psynergy Helm Splitter in its ability to kill a foe in a single shot. Annihilation appears as a sudden, violent physical attack that creates an explosion and a kanji upon impact: the kanji differs depending on if the instant-kill attempt succeeds or not. If successful the kanji is 殺 (korosu) meaning "to kill", if unsuccessful the kanji is 滅 (horobiru) meaning "to ruin, to destroy".
Annihilation is a very powerful and extremely practical Psynergy to use. The ability to one-hit-kill means that the damage potential is much higher, and makes it valuable against some of the stronger normal monsters, even if it does not trigger against bosses. Furthermore, being available to a class series tied for the highest attack rating in the game means that the damage-multiplication of Annihilation basically guarantees that the adept attacking will deal large amounts of damage, even without the instant-kill, making the move practical against virtually all enemies. The hefty PP cost is also not a major drawback, as the Ninja class series provides the player with a moderately large PP reserve to draw from. The largest downside is perhaps the fact that it is outperformed in the very late-game by Unleashes such as the Sol Blade's Meggido, which triples attack for no PP cost. Even regarding this, Annihilation remains a very potent move available from mid-game onwards.