Thinking outloud,
I'm thinking brute (syn. for evil-doer, comes from the roman name Brutus) but it's not in any card that i know of..
Exodia is the only latin name that comes to my mind at the moment. (Plural of exodium, or "after-play" exodia always appears at the end of a duel afterall) but when used today in exodus it comes from greek, not latin.
Necro- is greek though, but
Exodia Necross is darker than the other exodia, with its common pieces that might have been forbidden because of their wrong-doing,,,
Begone, Knave! features a roman-soldier, and knave is a synonym for evildoer, could this be the other card that needs to be compared to...
The purple is a distinctly Roman colour, but
Messenger of Peace isn't exactly what i'd call dark.
Abyss Soldier, it returns the monster to the hand like begone knave, and an abyss is a really dark place.
Abyss comes from late latin, although it appears in greek too, or even older than in latin, but it means bottomless.