No one can stand against the void. If the Void gets to Runeterra, or anywhere else in the universe, It's game over. They are an endless horde of horrors, Kog'maw's a literal living siege engine, and he is the larval form of a species that is freaking huge. The Void has always been portrayed as something that cannot be stopped, only delayed. The only thing that helps is that each creature of the void has it's own will, so they would interfere with one another, but that only gets the word so far.
They are honest about being monsters, but the Apsects are not gods. They are worshiped as gods, but they are not divine beings. The Targonians only think of them as divine, we know nothing about them. They use the fact that they are worshiped to get their hosts, Pantheon killed, by your own admission, his worshiper. yes, he's coming back and might be in there, but Atreus is honored for committing suicide just to have his corpse used as a costume. It's like a religious horror story
They cannot win this war. the void has always been portrayed as a Lovecraft/H.R Geiger nightmare. They cannot be stoped by anyone, gods or mortals. That's why Kassadin has his groupies and Malzy keeps trying to get rifts open, because if they were already here, there would not be a story.
What makes Zoe really interesting is we have the perspective of someone who has really lost touch with what it means to be human. That's why she's always trying to reconnect with people, she wants to play with the other kids. However, incredible ancient knowledge combined with innate immaturity creates what is to me a compelling character.
Well, I'm glad you like her. I think she comes across as immature and unusually chipper for someone who knows her family and friends are long gone. I don't like Riot has done a good job to show her trying to reconnect to humanity. It seems she just treats it as another game, but that's just me.