Once laughed off by her peers, her preparations served her well to fend off the corruption of Difeng City long enough for help to arrive. Who's laughing now?!

Part 5 of the Honkai Ball Z Series!

Discover Professor Youyun in her lab, moments before the corruption began to overtake her beloved homeland. Will you be the one to help her hold back the tide? Or are you an agent of chaos, an instigator of doom that she will have to defeat?