It's all right. It's not bad but it's not good either. Usually I apprehend the aftereffect of having finished reading something I really like, but here I just wanted to see the ending and get it over with.
The art is nice and it has some cool characters but that's about it. The whole premise "curses and cursed energy are born from negative emotions" is quickly left behind to let place to magic users fighting each other with their very own special little technique and bullshit explanations sprinkled on it. Why do some people have more energy than others? Who cares. The story is full of plot holes and retcon moments so clearly the author barely gave a shit too. Oh and don't expect answers to most questions from the ending because you won't get them.
At the end of the day it's your basic fighting shonen of 200+ chapters with the typical issues of this genre: power creep, power-ups out of the author's ass, unexplainable moments of infinite stamina and retarded twists (the fucking "binding vows"). The last fights are so over the top, I felt like I was reading DBZ sometimes. Again, it's not bad, but once you've read one you've kind of read them all.