I cannot characterize this as one of Statham's best. It was an OK movie.
Statham is an elite assassin. After considerable thought he accepts a hit he executes on his own best friend and mentor. Somehow this seems more compassionate than having the mentor killed by someone else in a more barbaric fashion. Then sometime later - he takes on the mentor's son - as his mentee.
There are some nice twists, and exciting scenes. However, there are many parts that just come across as too fabricated (guards hearing a single bolt fall on the other side of a wall, and immediately concluding that an assassination took place rather than a much more likley O.D.).
The film could have used a bit more character development. The Mentor's son seems very 2D - with psychological problems. Strange for a shoot-em up action film... but it would have helped.
A mediocre effort. Some good action, and suspense.