Yang Yi didn't know what exactly Brian planned to do after his release, but he was certain that Brian would definitely be up to something.
Brian had spent nearly thirty years in prison for a woman, and whether he now loved or hated her, the most important thing after getting out was certainly to find her first.
But Brian would not be satisfied with just finding that woman, for too much love and hate were involved. What exactly Brian wanted to do, and how he would do it, was something no one but himself could possibly know.
Many things a person cannot do alone. Yang Yi needed help, and his first problem to solve was the Destroyer. Although Hank and the others each had their strengths, they were only of assistance; they were no use in a real fight to the death. Bringing them to take on the Destroyer would be tantamount to suicide.
And Brian also needed help.