ex-keine
The Hakutaku form of Kamishirasawa Keine.
The nickname comes from the fact that Keine is the Extra Stage mid-boss (or "EX mid-boss" for short) of Imperishable Night in this form.
As a joke, fans commonly say "Caved by Ex-Keine."
See also
The following tags are aliased to this tag: ex_keine and exkeine (learn more).
This tag implicates kamishirasawa_keine (learn more).