An angel created by a god of destruction.
The blacksmith to create the swords of the soldiers.
Working tirelessly for eternities. He was scolded, he was beaten, he was caged.
When he begged his god, begged for mercy, for even an angel can only take so much. He was nearly destroyed.
He was fortunate. His only friend, heir to godhood, saved him. Sacrificed a halo, a literal embodiment of power and holiness, to send him down from Ethereal skies into the mortal plane. 

He built a new forge on the Mortal Plane, isolated. Mortals were fickle things of course. Any he grew to enjoy would surely die in a blink of his eye. So he stayed alone, forging. For nothing. For no one. Not even himself.

He is blind to the passage of time. Estus was a thing of myth. Until he met the merchant. The merchant wished to barter, to take his creations and give him raw material. And Estus accepted.
This merchant introduced him to many mortals, and standout was Mnstr-27. She wasn't eternal, but she wasn't mortal either. Her village stood as a place of hope.
When the merchant disappeared, Estus had lost his concept of time. 13 years he forged and worked. But as once empty shelves piled up, concern grew.

Visiting 27's village terrified him. Ruins, void of life. The body of his closest friend lie eroding in the center.
She was not a corpse though. Estus made it his objective to repair her. Then came the question, how to reactivate her. The risk was high, and it was frowned upon by Ethereal standards, but he had blessed 27 with his flame. Possibly the most intimate acts an ethereal could do.

Mnstr-27's mind was not something he could fix. He watched her distress, her pain, her dissent into self-isolation. He wanted to bring her calmness, to cool her down.

He could see Mnstr-27 needed something to protect. Something to nurture. So he built children. Two tiny robotic ethereals. He should have felt shame in this act. It was a god's exclusive right to create ethereals. But he did not, and it shocked him.