A Massacre

Davis was almost overwhelmed when he managed to kill hundreds of Vacuous Beasts at the next moment. However, this one large-scale attack using death energy instantly took away ten percent of his soul force. 

It must also be known that his Everlasting Samsara Tribunal Soul produced reincarnation energy in default, so when he caused splitting to take place in order to produce death energy, he was able to produce two times the amount of death energy with ten percent of his soul force.

So what should've cost him twenty percent of his soul force cost only ten percent, and this could be said to be an advantage but also well in line with using reincarnation energy that takes more energy than life or death energy!