I'm sorry for all the lore I'm about to dump because I'm not really a writer and it's likely not good, but I'm just doing my best to describe things.

Synthia's story starts with someone else's, a Runec scientist named Maria who ended up falling through a rift which transported her to the universe that came before the creation of the main one, a dying universe with no living gods, rapidly shrinking as more stars burn out every day, where life is a struggle, she tried her best to build some sort of life in this new bleak world, she calculated which planet would likely to be last consumed by the encroaching void, a small and snowy planet, a decent few residents.

As the years passed she began to work on a child to call her daughter, using Runec cloning technology, building a vat for her to be grown in, she used human DNA as a template, but as her child grew in the tank and the void grew ever closer, time was running out, and people got more desperate.
In the final days people had come to the little planet to claim what little meaningless riches the could, robbing and killing many of Maria's newfound friends, shr locked herself in her lab as existence crumbled around her, the crushing weight of the void closing in, looking upon the vat go see her child wasn't barely alive yet, she'd never get the chance to raise her, play with her, it had taken far too long.

But as the void closed in, all the universes energy was being compressed into one place, this vat being at the very center, the child's eyes opened, Synthia has been born.
All the energy and magic, hopes and souls of the universe entered the husk, creating an all powerful deity, the void was bounced back, the universe began growing again in a huge explosion of energy.
And from this point Synthia would begin experimenting with her ability to create, first making the demons as a sort of test, the first form of life, and then she would make the dragon gods, who would go out and create, helping Synthia fill the universe with more life.

Basflimans were the first non-demonoid race to be made, which is why they tend to be so arrogant.
As the universe grew and matured, she did as well, a tall pale lady with hair like a portal to outer space, the machinery which was with her in that vat, still firmly attached.

Anyone else who ended up surviving the collapse of the past universe, such as Maria herself, also got a ticket to godhood, though not as nearly as powerful as Synthia, I like to call these mortal-born pre-collapse gods “The Perennial”
Synthia’s mother Maria became the deity of time, luck, and Karma.