I really like how Kobayashi is handling the Core Medal and Cell Medals concept. The Core Medals were what the Gaia Memories weren't, they are a source of unlimited power and it really gives a sense of real danger and fear. Both the Gaia Memories and Cell Medals rely on one's greed, but in OOO's case, the greed of human manifests itself in a yummy, which is basically a reflection of the victim and their greed. A monster, which is all greed is. At anytime, Kazari, Uva or Mezuru could come out of nowhere, pop a medal, and monster that reflected our individual avarice would appear, and started to covet what we covet, food, money, dare I say it? Sex? Though that'll never happen.