So basically Sousei no Onmyouji starts off like any Shounen or Supernatural manga with the Protagonist being aloof. But slowly it progresses to become an enjoyable read.
A story line where the travel from one world to another fighting corruption/kegare, makes the manga super interesting. I loved the manga because there arent many mangas with the kind of pace Sousei no Onmyouji has and it will be really nice to see how things turn out for Rokuro-kun and Benio-san.
All in all i would really rate this manga an overall 8/10 atm. Might change according to how the story further develops(Hoping for the better).

PS: If you do watch the anime before reading the manga please do start from chapter 14 of the manga so you can get any context of what will happen later on in the story itself