Yeah, it's what I suggested few pages ago. An Avernus dlc would be awesome, with Karlach's questline being a side mission and it can trigger only if you bring her along with you.
I'd honestly love to see Zariel. I've read a lot of interesting things about her in the forgotten realms lore. And since we've seen the gods of other companions (Vlaakith, Shar, Mystra), would be sweet if Zariel was added in the list.
