Bai Zemin's group had planned to sneak into the building to ambush the Zombie Leader, and by killing it the zombies would immediately lose the only intelligent being who gave them orders and could organize them as a real army.
By accomplishing this, the Transcendent faction's assault team would not have to worry about missiles from the warships and could rest easy in the fact that the Zombie Leader would no longer have the capacity to launch a nuclear missile in the midst of his desperation.
Those in charge of killing the Zombie Leader were Sun Ling, Bai Shilin, and Luo Ning. With the strength of these three ladies, even a level 180-190 soul evolver would succumb.