Finally designed the Other, after who knows how long.
Anyway, meet the personification of Death, and the Allfather of the Universe. Like the Great One, the Other is considered one of, if not the most powerful spirits in existence, having mastered the power of Death and being one with it.
It is the duty of the Allfather to manage and guide those who have died in their respective afterlife; those who have achieved transcendence are awarded the path to the Great Haven, and those who have dishonoured the living are punished in Hell. There are some that are given the choice of reincarnation, though they lose memory of their previous life. All these tasks are watched over by the Other, whom keeps a close eye on them all.
While his duty is to the Dead, the Other occasionally visits the Living to offer condolences and wisdom. As the father of the Ancients, he is awarded time to be with his own children and with his beloved, the Great One.
As a primordial being, he could not interfere with anything that transpired in the Core Universe, which is why he did not have an active role in battle during the Great Conflict. This prevented him from protecting the Ancients from the wrath of Umbra, whom had abused the power only the Other could safely use. As such, he trusted that his children would find a way to bring peace.