I mean they may live in a host's forehead.

[He gestures across his face with his free hand.]

Though some might completely overtake a human mind if they are willful enough. And some embed themselves elsewhere...

[His own True Rune is snarled around his heart, squeezing it in icy talons with every beat.

The hand held in front of his face clenches into a fist then drops back to his side.]

Wretched, awful things, truly.