Aura of the Forge

Morgothal feeds the fire in you and fire radiates from you in an aura with a 15-foot radius. Until the spell ends, the aura moves with you, centered on you. 

When you cast this spell, you can designate any number of creatures you can see to be unaffected by it. When a creature enters the area for the first time on a turn or starts its turn there, it must make a Dexterity saving throw. On a failed save, the creature takes 3d8 fire damage. On a successful save, the creature takes half as much damage.

Morgothals fire deals an extra 1d8 fire damage to undead creatures.