Coat of Flame

Upon snapping the birch stick in half, glowing lines begin to snake across the caster's body, emanating from their hands. After covering every part of their body, the lines exploded outwards with magical flame that remain engulfing the caster's body afterwards. The flames can be any colour the caster desires, such as black, white, or blue, for example. 

When cast at 4th level, any creature within a 20ft sphere of the caster must make a dexterity saving throw against a difficulty check of 15 to see how well they can avoid the flames that explode out. When cast at a level above 4th, the range of the explosion will extend by an additional 20ft.

On a failed dexterity save, any creatures within range will take up to 5d8 fire damage. On a success, they will take half. When cast at a higher level, they will take up to 7d8 fire damage on a failed save.

Any creature who makes melee attacks against the caster when the spell is active will take up to 3d6 fire damage. When cast at a higher level, they will take up to 5d6 fire damage.

When the spell is active, the caster will automatically fail any attempted stealth checks as they are on fire.