Incense of Distilled Death

This black incense smells of fresh earth and ash. You activate the incense by lighting it, whereupon it fills a 10-foot emanation with oily smoke and potent void energy. Undead creatures, including incorporeal undead, gain fast healing 4 while in the area; though this healing comes from void energy, it doesn't negatively impact living creatures. Once lit, the incense burns for 1 minute, and it can't be extinguished.