As his strength rose, the number of souls Roy obtained gradually increased, but at the same time, the consumption also increased.
After spending more than 1,400 souls to create his own demon weapon, Roy only had less than 800 remaining souls. Among them, 600 were the high-grade souls that he had obtained from César. Roy used all of these souls to create Magic Energy Growth Potions.
Thanks to the Magic Energy Growth Potions, Roy's magic power rose much faster than other demons. After turning the 600 souls into Magic Energy Growth Potions, he gained a total of 712 points of magic power.
From the looks of it, these high-grade souls were best used to make Magic Energy Growth Potions.
After his magic power increased to over 1,300, Roy successfully reached the level of a middle-middle-rank demon. Once he doubled his magic power, he would reach the top-middle rank. At that, he would have to advance to high-rank demon.