Tower of God's power system, otherwise known as Shinsu, is incredibly unique. Even among some of the most beloved Shonen power systems such as Nen, Spirit Energy, Haki, Devil Fruits, Chakra, and so on, Shinsu is well-known. This is a huge compliment to the writing in Tower of God, as one of the most difficult things for any Shonen series to come up with is a power system and the rules that govern said power system.