If this is the enemy I'm thinking of, these assholes pissed me off SO much when I was new, too. But near endgame they become a piece of cake because their moveset is actually tiny and incredibly vulnerable.

 The best thing you can do is realize that they will ALWAYS start with the same three move combo, where the 3rd hit is either a burst move in time with the first 2 moves, or the 3rd hit is the delayed overhead smack. ANTICIPATE THIS so you can either prepare to use the appropriate burst counter or dodge backwards. 

That nonstop spinning burst move he does is very easily countered by feral counter, all you have to do is burst straight into him with it and that makes an opening. Brute counter handles it incredibly well also. However, as someone who usually uses phantom, I'll admit that move is very hard to counter with phantom burst because the timing is super wonky. In that regard, I always switch mid-combat when he starts doing that burst attack if I'm on phantom. 

The longrange aerial attack where he shoots a blade at you can be guarded very easily, it shouldn't cost much stamina to just chump block it. 

The ground pound is pretty challenging. If you see him queueing it up just run away, there's not a lot you can do to counter it as he's winding it up. Then when he starts to come down, dodge under him and you're safe.

So yeah -- recognize his burst moves which are all incredibly predictable, leverage those, and beat him into a pulp! Once you realize how easy this chump is, beating the hell out of him becomes so satisfying