I first tried to come up with a name for this guy by taking negative adjectives like ''treacherous'', ''secret'', ''ruthless'' (the most common traits in Star Wars villains), and several others, and creating names derivative from those words, much like the name Sidious was created from the word Insidious. Then, like you suggested, I had resorted to Latin and then Greek words, the latter indeed seeming much more appropriate.

As for the title of Darth, in this case it is fundamental to this character's structure. I'm aware it is often mistaken for a first name or simply awarded to characters who have no justification to carry it, but I wanted the villain to have an aura of discipline and skill to him, as well as to be an imposing figure, as opposed to the heroes (for lack of a better term) who are inexperienced and unsuspecting of what is to happen. Thus the title of Darth here implies the typical training given to the Sith who bear it.

That said, I really like the names you suggested and I'm very inclined to use them (Except for Rego, that out of a misfortune of fate translates to ''ass crack'' in Portuguese ._.). There is still time for more changes before I get to narrate this story proper, but thank you very much for your help.