Dire Spellcasting

Prerequisite(s): Diehard, Endurance
Benefit(s): While your missing hitpoint total is greater than 120, your effective caster level is increased by +1.
This bonus is increased from +1 to +2 while your missing hitpoint total is greater than 160.
This bonus is increased from +1 to +4 while your missing hitpoint total is greater than 200.
This bonus is increased from +1 to +8 while your missing hitpoint total is greater than 240.