hey i was wondering if anyone could explain to me what briarhearts are? i know they are created by hagravens and that there existance is created through dark arts of some kinds, but what exactly are they? does anyone wanna elaborate? please.

As far as I'm aware, the Hagravens use some kind of ancient magic and replace the human heart with a Briar Heart. In terms of "real life" mythology though, I have no idea.

Just accept it for what it is, whatever that may be. :/