Starlight

Starlight is a black-clad mage, found lurking on a small island in the southeastern corner of Buccaneer's Den during the time of Ultima IV.

Description
The dark wizard would claim to be a practitioner of black magic, and a caster of particularly powerful Magic Missile spells. After asking the Stranger if the hero could cast the spell, Starlight suggested that, instead of the formula given in  Book of Mystic Wisdom, the Stranger try using the wizard's own mix of reagents: a single black pearl and a single part of sulfurous ash (instead of one pearl and two ashes).

Trivia

 * In the Nintendo remake of Ultima IV (where most names were omitted and dialogues significantly modified), Starlight can be met in the same location. Instead of talking about the Magic Missile, Starlight will reveal that by using the password "SELECT" one may purchase Manroot at apothecaries. This only works in the Nintendo remake.
 * Starlight is the most likely candidate for the Man in Black that some characters talk about in the Nintendo remake of Ultima IV. In fact, in the original versions, he is the only character described as "a mage dressed all in black".