Eleleth
While referring to the direct offspring of a mortal and a god, this is very uncommon. Mostly because the gods do not have the ability to enter the mortal realm themselves just as no mortals has ever crossed the Cosmic Breach. There have been a handful of exceptions throughout recorded history but these are mostly technicalities except for one. Even mortals rarely can cross the breach, only when they have entered into a state of reverence that they must choose between becoming a god or returning to their mortal lives. For the Eleleth these are known as Veneraris and for the Ornir, the Einhjar. Lesser beings from the planes and mortals can end up on the other side of the breach through rare black portals but relationships with the powerful deities is unlikely as it would draw attention from beings above them. The next story getting away with it for decades is a rarity and still misunderstood in how it was allowed.
A part of a god can be sent down to the mortal plane but the being has its own sentience and can obey or abandon there gods once given life. That is why these can be risky but the Eleleth have sent down Soels, beings born in the Black Ocean and gifted the opportunity to take form in the mortal plane, usually to pursue a goal for their deity. The Ornir have a similar ability to create a Drengr, also sent to the mortal plane to achieve a goal. Others have also been pulled from the planes in the Black Ocean to Galfin but they still have a master, even if they didn't get sent directly by them. Paimon was pulled from Baan during a botched sacrifice, Rezial of the First House would have no idea that Paimon is on Galfin but Paimon is technically one of the Drengr of Death.
Also a note on gods not being on the mortal plane, one god was caused enough issues in the bLack Ocean that rules were bent and broken millennia ago for Merkayne to lock his brother Vlox within the Pit, a location the brothers built in tandem during the 2nd era.
Genetic Ancestor(s)