The Watcher of the Mists
Energy Substitution (Metamagic)
Prerequisite: Knowledge (arcana) 3 ranks, one metamagic feat
Choose an energy type of the following: acid, cold, electricity, fire. When employing a spell with the acid, cold, electricity, or fire descriptor, you can modify the spell to use your chosen energy type instead. The altered spell uses a spell slot of the spell’s normal level.
The altered spell works normally in all ways except in the type of damage dealt.
You may take this feat multiple times. Each time, the feat applies to a different energy type.