Daemon Blood

Daemon Blood is a reagent used by the magic school of Necromancy in Ultima Online.

Ultima Online
The great power of Daemons also lives on in their blood. Having taken a hint from the reagents Blood, Dragon Blood and Daemon Bones, which retain their properties and are very useful, the Necromancers managed to gather the blood of these fiends of the pits. This blood not only adds power, but also and unholy component to a spell, resulting in some of the darkest spells of this school of magic.

Trivia

 * Daemon Blood was planned in Ultima VIII, but ultimately dropped.