Demonic Flame

You shoot a beam of blood red energy anywhere within range.  It bursts into disgusting ooze and flames.  Each creature in a 20-foot-radius sphere centered on the point must make a Dexterity saving throw.  On a failed save, they take 10d10 fire damage and their constitution score is temporarily reduced by 1d3.  On a successful save, they take half damage and don't have their constitution reduced.  They regain the lost constitution points when they finish a long rest.