TAINTED SCHOLAR HoH p113
P115 Blooded Metamagic: This secret allows you to apply a metamagic feat you know to a spell you cast by paying an additional cost in blood. By draining your own blood, you can enhance your spells without using a higher-level spell slot. The cost is a number of points of Constitution damage equal to the spell slot adjustment of the metamagic feat.

CALL FORTH THE BEAST
Corruption Cost: 1d4 points of Constitution damage.