Needs review
Source: Encyclopedia Arcane: Battle Magic

Description: You are able to exceed your daily allotment of spells by sacrificing your Constitution

Prerequisites: 3rd Level Spells (Arcane or Battle Magic)

You are able to cast one or more spell of up to the highest level you know. This spell does not have to be prepared (if you are a wizard). Immediately after casting this spell, you suffer 1d4 temporary points of Constitution damage. This feat may be used as many times a day as you wish but constitution damage is suffered with each use.