Modiphius has released a 15-page Iconic Villains NPCs PDF for Star Trek Adventures, which includes Gorn Captain, Khan Noonien Singh, General Chang, Q, Locutus, Lore, Gul Dukat, and the Borg Queen. You can download it for £3.99 from their website.
Harcourt Fenton Mudd !!!
... would be a potential recurring character. He's a con man (and easily duped himself) so he might be a Villain or a Comic Relief.