Heroes can definitely challenge the gods,
@EzekielRaiden!
By going with a less "Western Theology" and more Early Semitic/Early Mediterranean angle we open up a lot of options in how people interact with the gods. And by diving whole-body into a Pulp Adventure style godhood, we crack that puppy even wider.
In addition to the Eight Divines, 6 of whom have cursed the world, there's also going to be lesser Manifest Gods. These entities will include powerful elementals, undead, fey, and even outsiders of various styles being worshipped as physical deities by cults they typically protect and/or control.
For example, the Island of Eroga on the Khufu sea, a former part of the now defunct Ellenic Empire, has Rovara the God of Love. Rovara exists as a physical entity in the world, flesh and blood, and is incredibly powerful. During the War of Transgression Rovara directly battled against the "Strange Gods" of Ancais to protect his twin islands and their occupants. He's said to be a tall, beautiful, powerful humanoid with the softest and fluffiest wings imaginable, shining and pink.
He gets his title by falling in love with mortals who live on the islands. Whomever his heart wends toward is immediately elevated in society, given festivals and parties, food, wealth, power, whatever they desire during the courting period before they are delivered to Rovara to be wed to the God of Love. This usually happens a few times a year, but during the years he fought against Ancais, it's said he loved -most- voraciously up to three dozen adults in a year! Love restores him, after all.
Meanwhile Ancais' whole story is that they were the most technologically and magically advanced people in the world. They had their own gods and called forth -more- from the heavens, making signs and symbols to call them forth from the darkness between the stars to join the Acain people on this world... Until eventually, in their hubris, they called upon a destroyer god. A wicked deity who pressed their people into war against the world. A God of Conquest... (Aliens. Not D&D style Deities)
Most of the Strange Gods were destroyed with Ancais. But not all of them were on the landmass when it was cast to the bottom of the Shallow Sea. And they yet live around the world. One such god is said to remain in the depths of an Ancais fortress-temple at Sepfar, where Ashuro the Mad has spent centuries building his ziggurat upon and around the ruined temple, to contain the God and take it's power for himself. The Altar of Ashuro, as the Ziggurat is called, is now host to sacrifices as Ashuro tries to force that God to give him whatever it is he wants.
Put simply... Players should be expected to be capable of killing evil gods and meeting benevolent ones by level 10. But even the benevolent gods will often be strange in their logic or actions.
As far as -attaining- godhood... That's another question, entirely, that will be left up to Narrators. There's no way to know for -sure- that the Flower is, in fact, Nefia the Martyr who sacrificed herself to see Ancais defeated during the War of Transgression. It could be a deity created, whole cloth, by combined faith. It could be some kind of interloper answering to her name in order to gain power for itself, or it could be Nefia's spirit elevated to the Divine...
But because "Godhood" is something that can be attained by those who have great power, anyone could be a "God" so long as their power were mythic enough. A Lich, by most people's definition in this world, would be a god. A Petty one. A Local god. But definitely a god.