Trickling Arrow

Your draw a line of your own blood through your skin. A bubbling arrow of blood hurls toward a target within range and sinks deep into their chest. Make a ranged spell attack against the target. You expend a number of hit dice, up to your hit dice maximum; on a hit, deal that much necrotic damage to the target. If you have fewer available hit dice than you intend to expend, you also suffer the damage.