The Dragon Prince is a recent high fantasy cartoon from the creators of Avatar: The Last Airbender. Fans of the latter will remember it as the well-known textbook of magic and worldbuiliding it is. Dragon Prince is good in similar ways and even better in others.
Namely, it absolutely nails the mysterious evil ancient magus trope. The elven archimage Aaravos gets very little screen time, mainly because a lot of the show is spent hyping up and preparing the viewer for his arrival. When he does appear, it takes another three episodes for him to speak... And when he finally does, the gravity of the moment is almost unbearable.
It's worth noting that at this point fans know very little about this guy, because the very attempt to research him results in reality-bending-magicks... But we still get a glimpse of his character and his methods of asserting his will through brute magical force, and by instilling fear.
EDIT Thinking about it Aaravos has really heavy Black Rose vibes, with the secrecy, "smoke and mirrors", immortality, blood rituals, seductiveness, and knowledge of powerful magicks... I love it.
Oh, and *that subset of the fandom*~~ the fangirls~~ are absolutely losing it right now.
Frankly I'm swooning too hard to write more, but it seems to me the overlap with League's ancient mysterious evil sorcerer is fairly large, and it's worth drawing some Vlad inspiration from Aaravos... Who by the way kind of looks like if Vlad got a Celestial/Darkstar skin.