Marcus fight is easy once you learn what to do
I mean, is it really
easy?
A low HP, defenseless character with deathwish AI and random initiative that more often than not makes skilled players lose nearly every time first turn unless you save scum multiple times until random luck or bizarrely convoluted tactics let you scrape by isn't exactly what I'd call an "easy" fight.
I love the intent of the fight, for sure. The surprise angle is
great. But given all the complaints and Larian's need to hotfix it multiple times, I'd say it's more like a cool event is ruined by an extraordinarily difficult, poorly designed fight.