Burning Blade

A gout of flame leaps from the top of your closed fist. The fire coalesces into a burning blade of growing intensity. You can use your action to make a melee spell attack against a target within 5 feet for the duration of this spell. On the first round the blade deals 3d6 fire damage and increases by 2d6 each additional round it burns.

At Higher Levels: The duration of this spell increases by one round for every spell levels above 3rd.