Rise as a Demon Lordress

Just another Reincarnation story. Unforseen circumstances leads Ji Riyu to her death. When she reawakens again she's just a weak demon trash. But after encountering a strange item she learned knowledge of the world and many languages. So if I eat cores of monsters or humans, I can become stronger? The life of a trash demon that rose in ranks eventually creating an overpowered fortress of demons and the like.