Calling the Shadows

As you concentrate, shadows and darkness seem to pull in towards you like tentacles from the room and all forms in it.  All fire light extinguishes within 10 feet of you shrouding you in darkness. This includes candles, torches and small camp or cooking fires. You must have Dark Vision to see into the darkness created by this spell. Any light source aimed at the caster or tossed into the area of effect will only illuminate half their normal area. A light spell will dissipate all this spells affects.