Sol Invictus (The Answer to Pursuing Gold)

[Reposted from AO3]
Solaris does not want to be referred as a "Boboiboy".

His whole life has always been fabricated to feed the expectations of others, from being the personification of gods to mortals to being weaponized in an intergalactic war and lastly, a proxy identity to a human vessel of whom he once saved.
He does not control who he became. But he also wants to know what it's like to actually do.
Alas, this universe is never kind, and he is stuck to serve an organization blinded by hero complexity, chained by the mortal emotions he was forced to acquire from his experiences.

That is the fate the cosmic spirit was thrown into, but this 'fate' is not set in motion in a universe where he doesn't exist.

And so with the aid of a mysterious deity, he finds that freedom can sometimes be a feeling, a place, a person, or a whole new existence entirely.