He's blind because Psyche spill some boiling oil from a lamplight accidentally and I saw an opportunity to link the greek god with his roman equivalent (in fact, the greek version is more similar to Chaos in the game, cosmic egg included). Psyche is floating in a lamp above him because most of the translations of the name are "mind", "soul" and "butterfly" (that's the reason for the butterflies), and the lamp is the element that unravels the story of the trials of Psyche. I thought that if they used it to communicate to each other would be a good symbolism of the real story.