How to beat Mission 4?
A. This boss seems to have an internal counter. As you melee him, his counter will build up and he will block continuously. After time, his counter will drop and he will stop blocking. Run to side. Shoot, shoot, shoot. Then do a regular D attack through through him. And repeat. The key is to melee slow enough such that your last hit will be blocked, as indicated by the sound effect. This is important to build up your Style meter and will significantly decrease the time taken to complete the round.