During the time that the blood essence is burning, the cultivator will gain great power. It is power that can reach the second mortal coil and can be used to save themselves. But after the blood essence is done burning, the cultivator will be injured.
This injury can be mild, and it can be serious. It depends on how long the blood burning was going on. If it occurred for a long period of time, the cultivation might drop from the tenth transformation to the ninth transformation of the first mortal coil.
The blood burning also affects talent. Burning blood for temporary power will reduce the talent of the cultivator. In severe cases, that cultivator might never be able to reach the second mortal coil again.
This is why talented people prefer to use extraordinary weapons instead of burning their blood. They will only burn their blood when they are desperate.
