Starting in mid Chapter 2 the enemies begin to have like 3-4k shield on top of ~3-4k hp.
A purple equipped player Char at this point does around 200 damage per 2 ap used.
At the same time they begin to attack for 200-300 damage up to 3 times per turn(assassins can get to over 1k damage in a single turn) while your non tanky guys have like 400 hp and ~200 shields. I think my tanky has around ~1,4k effective health and can still get killed by a single trash mob in one turn if he does crit.
You can't cc or burst them because of the absurd shield and hp values and they often come in packs of 5+. Most of the AI range chars also completly ignore LOS and just shoot trough massive objects/ignore smoke etc.
So the only way is to cheese them with 4x teleport and necrofire. Or by using boring perma ooc stealth tactics from high grounds.
Just all that unfunny stuff which has nothing to do with actual tactis and just exploiting the game.
It just doesn't feel very balanced at all tbh. The first Chapter was rather nice and well balanced but the enemy shield values at reaper cost are just so much overdone that you really need full sourcepower for nigh every fight and still have to cheese it.