Hellfire Void (3.5e Spell)

This spell creates a large ball of hellish, roaring flames that envelop all within, blinding those inside and dealing 1d6 points of fire damage per caster level each round that they remain within. In addition, the area of effect is treated as an antimagic field.

This spell feeds on the magical energies of those inside, and can last beyond its normal duration so long as it deals damage to someone inside each round. The spell disappears if it does not deal any damage for an entire round if it has already surpassed its normal duration.