Lae’zel: The Slaughter, since Gith culture is militaristic and Lae’zel is a soldier through and through— she doesn't mindlessly kill or easily fly into a blind rage, but she still craves blood all the same.

Shadowheart: The Dark. Come on, Shar wants to plunge the world into eternal darkness, this writes itself.

Astarion: The Web, for his fixation on manipulation and gaining power in any way he can. Hell, even in his romance he was manipulating Tav/Durge at first, even if he realizes that security wasn't all he wanted.

Gale: The Eye, his obsession with knowledge and his need to know more was what brought him ruin and led him to the Orb, not unlike a certain Archivist we know.

Wyll: The Hunt, since he's literally primarily a hunter of monsters and other demonic creatures. Targeted by the Eye, maybe, since Mizora uses his bloodstone eye for surveillance and he's so worried about pursuing a romance with Tav/Durge because she's turned his own brain into a nightmare panopticon where he doesn't know if he's being watched so he always acts like he is.

Karlach: The Slaughter, for her connections with war and destruction— she's full of rage and violence but while I do think the fire caused by her engine smacks of Desolation, she's not been brought low enough to be a Desolation avatar in my opinion (even with her consuming other people's misery like one via Soul Coins).

Halsin: The Hunt, mostly for his animal connections and his obsession with tracking down the answers to fix the Shadow Curse not unlike the way you see mentions of explorers in the 1800s trying to find secrets in the more remote parts of the world.

Minthara: The Web, not just because drow and haha spiders but because she's fixated on gaining power, even if you recruited her the “good” way. Hell, you literally find her sitting on Ketheric’s throne after you kill him in the Mindflayer colony and come back up to the surface of Moonrise.

Withers: Not even an avatar, he's just The End, as the Literal (Retired) God Of Death And Everything Surrounding It.

Ketheric: The End, which is fitting not only because Myrkul is the Necromancer in the Dead Three trio, but because Ketheric's motivation for turning to evil gods (first Shar, then Myrkul) was because his wife and daughter died, and he couldn't handle that loss.

Orin: The Slaughter, for obvious reasons. Not the Hunt, mostly just because Bhaal focuses on the blood of the murder itself, not the chase beforehand. But I do think she's sharing winks with the Stranger, what with her being a Changeling and all.