Barloban's Wyldfyre Wrath

You stretch your arm out with one down low and one up high and rotate them in a circle until they have switched place.  You then clasp your forearms igniting yourself in bright green flames and push your arms out extending the flames out beyond your reach.  A 500ft tall cylinder with a radius of 30ft of wrathful bright green flames is now centered on you, and moves with you, that deals 10d8 fire damage, from a wyldfyre source, to all creatures of your choice that start their turn in the area or enter it for the first time on their turn and they must make a Consitution saving throw.  On a failure targets take an additional 5d8 fire damage and are stunned until the end of their next turn on a successful save the targets take half of the additional damage and are not stunned. Wyldfyre is a powerful source of fire damage twisted by arcane magic to turn the flames a bright green color. Fire damage from a wyldfyre source bypasses ignores resistances to fire damage and treats immunity as resistance for all creatures excluding fiends.