Disable

Disable is the Down-B move of Mewtwo in his Super Smash Bros. Melee appearance. Mewtwo shoots out a short beam from his eyes in front of him, and any opponent right in front of him that is facing him will be Dazed for a short period. If the move is performed whilst the character is already Dazed, he or she will fly off taking 1% damage, but will recover when they land. The disable will also send foes flying anytime they are in either a dazed state from say a shield break or in an aerial tumble. This adds new knockback such as dtilt to disable, or downthrow to disable. This combo is performed by hitting a foe with a shadow ball and while they are still in hit stun disabling them which will actually send them flying. Also if the enemy is rolling up the ledge using the r or l button then disabling them right at the end of the roll motion will cause them to shoot off the stage as well. The move is often considered impractical due to its short, narrow range (the opponent must be very close, in front of Mewtwo and at approximately eye level), but it can be used to disrupt an advancing enemy or stun them for a charged Smash attack. For a better use try wavedashing into it or jump canceling it which allows you to keep your momentum. Also of note is that the effect of the stun will last longer the higher the foes damage.

Origins
The mechanics of Disable have changed throughout the generations. In the first generation, Disable inaccurately and randomly disallowed the opponent to use one of its moves for a few turns. In future generations, Disable would disallow the last move used, adding more strategic depth, especially against high-PP recovery moves. However, its low accuracy and relative uselessness has made it rare in competitive play.

Trivia

 * Fox and Falco can reflect the move with Reflector, and it can bounced back with a Perfect shield.
 * In the Pokemon Mystery Dungeon series, the move Disable paralyzes opponents, and is actually quite accurate.