This is a parody of a scene from episode 10 of the original Neon Genesis Evangelion

Krad_Hunter said:

This is a parody of a scene from episode 10 of the original Neon Genesis Evangelion

Oh,that's LCL fluid! I thought she was about to try scuba diving in lava... and also that her hair had inexplicably not burst into flames.
EDIT: Or is it? I don't remember my Eva episodes well.

Raikou actually DID go for a dip in magma during the second Halloween event, terrifying the shit out of Ibaraki in the process, along with the other members of team "sneaks into your room at night".