Kill

Kill - also known as Death Bolt and Mind Blast - is one of the strongest attack spells available.

Spell Description
Casting this spell, an inescapable bolt of lethal energy is fired at the foe. Once hit, the target's vital fuctions fail for the duration of seven heartbeats. In almost all cases this one bolt is deadly, resulting in an instant kill. Only few monsters have the strength to withstand one of these bolts. This is the reason why most mages - especially those with less than virtuous motives - strive to learn this attack spell as fast as possible. No armour and no magical protection helps against it, although some monsters have a natural protection against death energies and thus this spell.

History
The lure of finding a way to kill a creature - or fellow person - instantly with magic caused such spells to be developed very early after magic was rediscovered in Sosaria. The spell known as Decorp was developed at the time of Mondain's reign and was there to stay, with the clic classes later in Ultima III developing the similar lethal spell Excuun. These wer even developed into the spells P and Zxkuqyb, which could kill multiple targets.

Even after Britannia was founded, the Kill spell continued to ejoy great popularity among mages, even though many magic teachers refused to relay knowledge about it to their students. It proved that the power to be a master over who lives and who dies was too much of a lure for many to resist.

Ultima Saga
After touching the temporal curtain created by Balthan at the end of The Forge of Virtue, Jordan is blinded by magic. The spell scrolls used to construct the time wall are An Tym, Xen Corp and Vas Lor. Balthan had been illuminating scrolls of Eighth Circle magic when Blackthorn took his master Felespar, including those that could "slay a man wherever he stood".

Quote

 * The magician sank slowly to his knees. "I used three scrolls: An Tym, to slow time; Xen Corp, to kill; and Vas Lor, great light to bind them together and because it was the only scroll I had left. I don't know what happened to the Xen Corp--" The gleaming wood fell from Balthan's fingers, "--but it's the other two that are blinding you."

- from The Forge of Virtue (Ultima Saga)

Trivia

 * Dragons are immune to this spell.
 * Liches, post-Ultima IV, tend to use this spell for an instant kill against the Avatar, making them very dangerous.
 * Kill works on undead creatures, even though the description in Ultima IV implies it should only work on living creatures.