Kill

Kill, also known as Raze, Doom or XXXX, is a magic spell that causes Instant Death to an enemy, with a hit rate much more reliable than the spell Death, which tends to miss.

Final Fantasy
Kill, also known as XXXX in the NES release and Doom in the Final Fantasy Origins release, is a level 8 Black Magic spell which inflicts instant death to a single enemy with a very high success rate.

The spell can be bought at Gaia and can only be learned by the Black Wizard class. In the GBA/PSP/iOS releases it costs 40 MP to cast.

Final Fantasy III
Raze is a Level 5 Black Magic that can be used by the Black Mage, Red Mage, Magus, Sage, and Onion Knight (in the Nintendo DS release). Raze instantly kills all enemy's whose level are not more than 3/4 of the caster's level. The spell can also be used through the item Devil's Sigh. Raze may be bought for 5,000 gil in Northeast Saronia or Doga's Village.

Final Fantasy XII
Kill is the Esper Zalera's main move that acts like Death. It is always 100% accurate, but the player does not gain EXP, LP, and Clan Points from the enemy.