Originally posted by TheMuser
By the time he was finally defeated, Ulic Qel-Droma had become a formidable Dark Lord of the Sith, second only to his partner Exar Kun.
- The Dark Side Sourcebook
The quote is saying Droma was a powerful Sith Lord, but Exar Kun was even more powerful.
Not that Droma was second only to Kun amongst all the Dark Lords of the Sith.
It's not that difficult to comprehend.