Gods and Goddeses have a part of them defined as the lower or weaker verision of themselves, but it's just simply their shadow self. A more locked away version of them, that also exist in the same place as the og gods and goddesses.
This ability is somewhat similar to what an angel goes through, but the only difference is that an angel going through an ego death is just a transition from one race to another, but they can transition back to their original race multiple times at any given moment, while for gods and goddesses they don't have that ability the longer they ignore their shadow self the more powerful, dominate and active they become in their daily lives which can be very troubling.
Just like how humans create alter egos due to trauma as a coping mechanism. Angels have ego deaths so that they can literally walk in the shoes of beings that they hate and look down on the most. Gods and goddeses go through something kind of similar but more emotionally demading.
This happens once in every blue moon, new gods and goddesses will split into two halves, while older gods and goddesses shadow self will appear from what seems like no where to challenge and disturb the peace a little bit.
But all they actually do is tap into a deep part of each god and goddess to reconnect once more. Some gods and goddesses stay connected, while some will be confronted by their shadow with the help of the moon.
One half is represented as powerful beings of "good" , or powerful beings of " heaven " , while the other half is viewed as evil or kings and queens of evil or the underworld.