Chant — David Cross

Professional assassin and martial arts master Chant is about to go from hunter to hunted in this thriller from the author of the Mongo Mysteries.
 
John “Chant” Sinclair is precise, patient, perfect. A highly trained killer with a mastery of martial arts, he's able to slip in and out of any situation, in any disguise, all while maintaining absolute control.
 
In a former life Chant was a soldier, but now he's the world's most wanted criminal, working for himself and taking only the jobs he wants. Governments want to either hire him or kill him. No matter the foe, Chant's skills have made him untouchable . . . until now.
 
Years ago, one man taught Chant to be a dealer of death, a warrior whose very name, Bai, strikes fear into the hearts of men. Now, Bai has been hired to take out his former protégé, and when master and student face off, only one will emerge victorious -- and alive.
 
Chant is the 1st book in the Chant Mysteries, but you may enjoy reading the series in any order.