'Gluttony's Eyes allows me to obtain the memories of the soul I consume, but for that, I need to overwhelm the willpower within them. And that is just the start. Even after overwhelming the ego in the soul force, fully assimilating the memories is not something easy to achieve, especially if it belongs to a powerful entity.
If I want to improve the power of the ability, I need to go to its core, and that is the Concept of Gluttony.'
Just like The Flow, the first ability he obtained directly from his past life's memories, Gluttony's Eyes principles did not reside in the Laws, but in the power of Concepts. If Cain wanted to improve the power of Gluttony's Eyes to consume the soul force of the Soul King and obtain his memories, he would have to master the Concept of Gluttony.
However, that was easier said than done. Nothing was restricting Cain's ability to perceive and comprehend the Concept of Gluttony, but there was also nothing helping him.
