One hit knockout

A One Hit Kill is a term used for attacks that, if successfull, kill the other player instantly. This is widely discouraged throughout the Mugen community.

Examples
-Nobunaga Oda, when the opponent has health lower than half -Sephiroth by Gulthor has multiple

"Untrue" One Hit Kills
Certain attacks aren't true One Hit Kills, but cannot be survived through normal means nontheless. An example is Metool's Giant Metool drop, which has 9000 attack power, a possible reference to the "Over 9000" fad. Most overpowered Dragon Ball Z characters have energy waves that deal damage at a constant rate instead of one extremely strong blow.