What World of Warcraft villain had the best overall arc?

Yesterday, I asked about WoW Villains who didn’t get as much development as we might have wanted. So now I’m back asking about the villains who did — whether it be a expansion-wide big bad, a character who pops up in quests and maybe a dungeon or two, or an antagonistic figure who never actually ends up in a raid.

I’m looking at you, Magatha Grimtotem — she successfully engineered the death of her rival Cairne Bloodhoof, escaped the vengeance of his son Baine and the Orc she duped into being her instrument Garrosh Hellscream, and made off with an artifact of elemental power and hasn’t been seen since. She’s sinister, manipulative, and is still out there somewhere without feeling like her storyline just trailed off.

Similarly, I feel to this day that Hakkar in original World of Warcraft has a very strong arc. He shows up in quests that lead players to the Sunken Temple, and after those quests he makes a second and very important appearance in Zul’Gurub, which wrapped up his storyline for a while thereafter. Even when he eventually came back in the Cataclysm version of the raid and popped up in Shadowlands it didn’t feel forced. Hakkar is out there, he’s a menace to Azeroth, and we’ve seen him enough times to know he can slither his way out of what could be certain death. He’s not the big bad of an entire expansion, he’s an opportunistic Loa who pops up to cause havoc and mayhem.

So what about you guys? Is there a villain in WoW who you think had a good arc, a story that made proper use of their talents and was satisfyingly resolved, if not forever at least for a time? Who would you pick as the WoW antagonist with the most satisfying character arc?