The Corruption of Aftioch
The god of debasement and corruption, Kakia, was one of the last gods to arrive on Palboria, and he found it a rich playground. After teaching the animals of Dentros' woods the pleasure of sport killing, Kakia turned his sights to the gods themselves. It was in the god Aftioch, herself a god of physical pleasure and indulgence, that Kakia found his most willing victim.
Aftioch was easily convinced by Kakia that the joys of the flesh included pleasures taken from relations with lesser beings. Aftioch needed little persuasion to slake her thirsts on the mighty forms of the demi-gods. It was from these revels that the giant races were birthed.
Kakia further established his trustworthiness to Aftioch when he vocally defended her when the other gods began to judge her for birthing mortal creatures. He worked his way closer to her and used her faith in him to further drive her corruption. When the mortal races arrived, she'd already been keen to find something new. From there, it was only a short step for her to lay with the animals of Dentros' woods.
The twisted offspring she produced were a blight on the land, magical creatures that held to no natural order. More representative of her corruption than her deity, Aftioch's children killed and destroyed as they chose.
Eventually, the gods banded together and sought to destroy Aftioch's tether to Palboria, banishing her so that her children could be annihilated unprotected. If it weren't for Seolous himself stepping in to save her, they would have succeeded. The King Above judged that the creations of the gods may be free to hunt and destroy Aftioch's children, but the gods themselves were forbidden from directly attacking any creation made by another god. Aftioch would forevermore be known as the Mother of Monsters, and her realm of love and lust would be limited to the mortals; no more would the gods themselves pursue their ardor in the physical realm.
How much of this story is apocryphal and how much is truth is, at this point, irrelevent. Many of the creatures identified as Aftioch's children do exhibit powers and abilities above those of the normal, mortal animals brought to Palboria by Dentros. No other suitable explanation for this has been found.