Commander Zhalk on Tactician
Shadowheart spell on him to drop weapon and buff ac on mind flayer . use little guy with haste to cheese away 2 cambions after 10th turn from the battle.
Laizaer can pick hes 2hander so shes probably gonna be the main damage dealer. If you save/scum she can hit him critically for 20+ damage.
You also can gather 3 crates+ 1 in room where shadowheart was imprisoned but that method worked in ea. Now if you blast all 4 its going to inflict only around 30-35 damage.