Dungeonosophy
Legend
Warduke the villainous warrior.
Yeah, Warduke from the LJN action figures, from the D&D Cartoon Show, from Mystara, and from Greyhawk!
Warduke the villainous warrior.
Aleena is a good choice although, as you say, she's presumed dead in canon.
I like Eric the Cavalier as a choice, but... as an antihero? Seems a bit harsh to put him in with folks like Raistlin and Artemis Entreri. Eric is a whiner and a coward, but he's not malicious. He's never killed an innocent (in fact, probably never killed anyone at all). I know that the strict definition of antihero is "a protagonist lacking heroic characteristics like morality, courage, etc", but still...
As for the Egg of Coot - phew. That might be too deep a cut.
Did Spelljammer and Birthright even have any notable characters? I can't think of any.
Arguably, there should be more characters from other media options. I thought very seriously about including Jim Darkmagic. Given how many people come to D&D through podcast views, there should probably be one or more notable podcast characters on the list. Maybe even some webcomic characters: how about Durkon from Order of the Stick? D&D, and D&D-inspired work, has gone far beyond the tabletop these days.
some of the less powerful wizards from the Circle of 8 (I don't know of the names) could make it into the hero group and the Wizard Rary who betrayed them all could perhaps be part of the villain group.
The problem with naming 12 Villains is, villains are supposed to be defeated - therefore they don't have much staying power*. Contrast that with the heroes, who each get multiple serieses of novels about them.
Are there any Living Greyhawk or Living Forgotten Realms characters that could qualify for the list? ('Diversity' of an unexpected sort.)
* For instance, in Star Wars, Thrawn made a profound impression but only survived for three novels. (He subsequently got retro-fitted into the Prequel generation for a handful of novels.)
Temujin of the Golden Horde (from the Horde trilogy) is somewhat an anti-hero.