Derek

Derek is a knight of the Knights of the Crux Ansata, found on the fourth level of the Abyss, who has specialised on working with gems.

Description
Meeting him during Ultima Underworld I, Derek complained how he had no good tool to cut his gems. The Avatar thus gave him the gem cutter received from Goldthirst. Derek was impressed at such humility to give away such a treasure and revealed to the Avatar how to get the Ring of Humility on the fifth level.

Later, he was rescued by Garamon when the volcano erupted.