The most common iteration of the origin of the pantheon is the following,,, At the start there were 13 celestial beings, shapeless motes of divine power. The first to take shape, Wela, Deity of Time, took a humanoid form, a thoroughly grey humanoid of mundane shape. Intensely amber earrings and irises formed on them, as well as a nondescript staff, with its own amber sitting at its end. And suddenly, there was time. The other beings were in awe of such a feat, some jealous, some unamused, some confrontational. But they had no shape to express themselves, so they made some. The next to take form was Terra, Goddess of the Wilderness, rooty brambled hair revealing a gorgeous earth genasi countenance, as well as a strong and grounded body. She took shape to be angry at Wela, but then realized how blissfully confusing it was to have a form. Earth cracked and expanded from beneath her feet, filling the world with alien shapes of soil, soot and stone. In an impulsive decision, Maer, Deity of Change was the next to mould themself, into a water genasi, their first form being a light blue masculine figure with unquestionably sparkling eyes. With this form, he brought unto the world a roiling wave of water to flood its alien earthy shapes with, deciding last-minute to only half-flood it instead. After Maer, an equally curious but more whimsical mote contoured itself a body, Auro, God of the Weave unveiling himself as an air genasi man with deeply purple eyes and lines etched into his skin. He inflated the world with air and wind, infusing each bit of it with a spark of his divine magic, which would eventually seep into every material in the world. This was an interesting world, but it was unperceivable. So the next to take shape wanted that to change. However, Argia, God of Light miscalculated when he manifested, a thoroughly winged creature of light, but as well-meaning as he was, he blinded the whole world with an inescapable radiant brightness. Rolling his metaphorical eyes, the strongest of the motes, Quietus, God of Ruin , took shape thereafter, seeing to bring balance by apparating as an individual silhouetted by its absolute darkness, and bringing a promise alongside his form, a promise to one day return everything to what it used to be, motes of divinity isolated in time. With his characteristic wit, Motus, God of Motion realized that there was not much space for grey in the world, either intense brightness or plunging darkness. So he slipped into a corvid form, and displaced Argia up in the sky, making sure that there were times of light and times of darkness by the movement of the sun. He also brought non-divine movement to the world, the earth could slowly shift, the water brought tides, and the wind often flowed, all without needing divine intervention. There were still six motes who observed and hesitated, the world now more rounded and sculpted in strange and mysterious ways. It was then when Maer and Terra had the first divine babies, conjoined twins by the wrist, Naspa, Goddess of Fauna and Pashu, Goddess of Flora, deities of fauna and flora respectively. And from their birth, life itself was born, but it was a very mechanical life, simply doing what it needed to live. One of the motes sought to change that, to spice the dull life that the divinities had formed, as Zheyli, God of Emotions fashioned himself into an incredibly attractive and consistently shifting humanoid form with colorful skin and attire. His presence infused life and the world itself with vibrant and powerful emotions of all kinds. Some time later, the next to decide to take shape were Ignis, Goddess of Civilisation and Kyun, Goddess of Hearth, the former sculpting herself as a fire genasi lady with regal clothes and perfectly flowing lava for hair, while the latter taking the kind shape of a motherly humanoid, a round face and understanding smile. Together and with Naspa they created the first humanoids, and civilization. Another mote was stirred into curiosity now, taking the figure of a male humanoid with a wrinkled countenance and sun-baked leathery skin, alongside a wide straw hat. Agrion, God of Agriculture taught and brought with him the joys and techniques of agriculture, hunting and cooking. Interest piqued by the dissemination of knowledge and teaching, Oculon, Deity of Knowledge quickly apparated a body into being, a humanoid covered entirely in eyes of all kinds and shapes, a deity of the quintessence of information. The last mote to join was unamused by this all, it just seemed boring. And so, when she joined, Polemos, Goddess of Conflict carved herself a strong body of muscle, and brought with her the first wars and conflicts, to make things a bit more fun.
With war and death, the gods decided to bring some afterlives into the equation. Each of the original 13 gods provided their own afterlife, Quietus providing one that would take souls from anyone who did not qualify for the other afterlives. As time went on, other deities also provided afterlives, but they are usually small and niche.
The original deities decided to also make a governing circle, this ideation spearheaded by Ignis. Three of the original 13 deities were either uninterested in joining or unable to (being too busy being the sun, and all that), so Argia, Quietus and Wela are not considered to be in the "Major Circle". Heaps of time has passed since then, many more deities have been born or created. While various were born by reproduction, many were born from 'joining blood', a process between deities that is just as effective and is done just how it sounds. Nowadays, the major deities tend to be more distant regarding mortal affairs.