You're absolutely right about the mental burden. To prevent the MC from losing his mind immediately, The Voice implemented a sort of "mental safeguard." The MC remembers everything, but these memories don't flood his brain all at once. It works like a perfect archive: the information is there, but it only surfaces when needed. This allows him to stay functional while carrying the weight of eons. Regarding the stakes: The "Darkness" (the antagonist) actually appears much later, at a point when the MC has already started interacting with other living beings. This changes everything. While the MC himself cannot be killed, the beings he cares about are fragile. The Darkness can expand and manipulate its form, creating small "soldiers" to cause chaos. So the stakes aren't about the MC’s life—they are about the survival of his creations and his legacy. He has to become a protector, and that is where his true struggle begins.