Miasma

Miasma (shouki) is a black emanation issuing from demon-gods such as Biblos and Morrigan. It spreads in three escalating stages and accompanies incursions of heretic magic and the creatures spawned by demon-gods.

Bearers of heretic magic tied to demon-gods are immune to miasma — as, for instance, Reina, within whom the power of the demon-god Morrigan slumbered.