+2 Red banner
Anointed One (Water Brand)
Alchemist (Merchant, Alchemist)
Banshee (Magic Link, Jinx)
Valkyrie (Divine Bond, Necromancy, Water link)
In fact anyone on the first place do. Sometimes I use Trean with all traits since he can take more damage than Anointed One but Anointed one can make basttles go faster if he manages to shoot his first spell before he goes down)
Using slime as well. Was working on soul farming team and since just got the king, trying out the following for combo soul farm and damage team. Still low level with the king and not sure how sturdy he will be in first slot but have already tried a few battles with:
Infernal King
Green Slime
Valkyrie
Shadowhunter
Can take awhile to get going but if aligns fast enough its just cascade/manafest with decent damage and souls. If lose king though, it can be hard to take stragglers out with just shadowhunter,