The Volt X Is a Formed a Bomb Bunch Back

You look up into the gray skies, but all you see are ash and flakes floating to the ground Drop blazing inferno purple flame rains down from the sky everyone make it dexterity saving throw. You would have your danger sense would apply seven I'm a teed and Elga rolls sufficiently Barney and chip your little too low and some of that purple flame hits you I'm a tiefling. So I have resistance to flame. If you say Just suckers his face change drastically What percentage of Barney's life are we looking at being gone here?