She was 'fanatically' devoted to her job.
a religious 'fanatic' [='extremist']
He is 'fanatical about' boating.
(..) When the High Sparrow is in custody or dead, preferably, and Margaery's back at Tommen's side, do you think the king will be angry at the outcome? You hate these fanatics as much as we do. You hate what they've done to your son. Do you want Lancel back? Or have you given him up for good? (..)2016 TvShow: Game of Thrones Title: Book of the Stranger Season: 6 Episode 4
(..) Please. All right. And now, how to avert disaster with our current predicament. This High Sparrow. I have dealt with fanatics of every description, Your Grace. Not setting them off, that's the most important thing. You are beset with enemies both within and without. (..)2016 TvShow: Game of Thrones Title: Book of the Stranger Season: 6 Episode 4