BM, the Bloodmage is the Mage of Blood.
Passive: Sacrificing flesh at an altar gives +1 piety.
Prayer Bonus: Sacrificing flesh at an altar improves the altar's effects slightly.
Restrictions: Pay a blood price of 10 points a turn. This price increases by 20% every update cycle. If you die by running out of points, you are free from the Bloodmage's effects.
Penalty: Triggered by going negative piety (impossible, really) OR by renouncing the god (stopping prayer of the god). Set piety to zero, and renounce this god (does not trigger penalty again). You die.
Non-egotist: The bloodmage does not care if you worship another god.
Vampirism: (7 / +23 / +170 piety) Your attacks heal back for you for 30% / 60% / 100% the amount that you inflict.
Bleeding: (6 / +24 / +120 piety) Attacks deal two marks of bleeding, up to 8 / 11 / 14 marks. For every mark that they have, do an additional 3% / 5% / 7% damage. Every turn one mark is dispelled.
Regeneration: (60 piety) Gain 3 points per turn for every mark of bleeding everyone has.
[REPEAT] Quell: (7*3^r piety) Reset the blood price to 10 points.