Darth Homunculus

Details
Race: Unknown

Location: Deceased

Occupation: Sith Lord

In Terms of the Heroes
The heroes first heard of Darth Homunculus on Umbara, learning that he had captured and shipped Tin, Saren's brother, to Katarr in order to create a nigh-unkillable abomination.

The heroes followed Tin to Katarr, where they encountered and killed Darth Homunculus, the first Sith Lord that the heroes have managed to kill.