This is a custom cosmetic mod. The 3D model of Yukari Yuzuki was set to be unaffected by light. An IK rig was used to play the animation of the survivors. Due to the material of the unit, it emits light in the dark. Also, because the Hiproot has been retargeted, it will float or sink if its height differs from the default.
For the terms of use of this model, see the following page.(This page is written in Japanese) https://www.vocalomakets.com/mmd.html