Urza's Rage

You create three rays of fire and hurl them at targets within range. You can hurl them at a different target.

Make a ranged spell attack for each ray. On a hit, the target takes 3d8 fire damage. The target is then marked with a rune of fire. As a bonus action, you can select one target with a rune of fire and cause them to explode. They, and creatures and objects within a 5ft radius take 10d8 fire damage, CON save for half damage.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, you create one additional ray for each slot level above 7th.

Deep in Yawgmoth's realm Urza stopped dead in his tracks and rubbed his soot-filled eyes. "Mishra?"