Issue: this boss is literally impossible to kill on some characters.
According to my understanding, it requires to back-attack with a floating/knockback cc 5 times in a row in short period of time.
Succession Maegu, for example, has only one floating (Tag) on 6 seconds cooldown, which means it's physiclly impossible to fullfill the mechanics. Other examples, as far as I know, would include Ranger, Guardian (cause she's too slow to back-attack), and possibly many other classes.
I think PoU should be a place to show off your skill and understanding of the class of your choice. This boss not only design favours some classes over others, but actually discriminates some.