With a sacrifice of one's own blood, divine embers ignite along the caster's forearm. Bestowed upon the wielder of this art is a torrent of flame to be commanded by contact with an enemy. But beware, once the flames make contact, they know not the difference between friend or foe. They yield not their scorn for none. The caster must make a Constitution saving throw, even if the attack misses. Make a spell attack roll on the target. On a successful hit the target takes 10d6 fire damage. The caster takes 2d6 fire damage on a failed save, or half as much on a successful one. Additionally, any creature caught within 5ft of the caster(exception of behind) are subjected to the same effects as the caster.  Any creature caught in the blast must make a Constitution saving throw or take 2d6 fire damage on a failed save, or half as much on a successful one.

If you target a plant creature, you have advantage on the spell attack roll.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d6 for each slot level above 4th(scaling applies to caster and additional targets).