Noragami2014

Kofuku:
[watching along with Hiyori] An ablution in this sense involves cutting flesh. This is a beating, one that uses Regalia Boarderlines.

Hiyori Iki:
A beating?

Kofuku:
As former humans, only Regalias can judge the sins of other Regalias.

Yukine:
[trapped in the borderlines] Let me out! Let me out, damn it!

Kofuku:
And once an ablution begins, it can't be allowed to stop until it's over, not until the Regalia has confessed and repented every last sin it bears.