My theory on what the true problem with the Runeterra world.
I am one of the few who still clung onto the dream of one day being able to play as ao shin, even when it was getting obvious he would never get released as initially promised. I still got super hyped, though, when they released the riot designer page for Aurelion sol with the first trailer. After watching the trailer, my brother looked at the screen and said "villain" because he had both the lines and personality of one, but once the lore came out about him, those who read it found that he was unjustly imprisoned and wanted freedom above all else, thus clearing his name. Upon reading his lore, it states that the targonians tricked him into wearing a beautiful cursed crown to tether the star forger to the pantheon's will, all stuff that you, the reader, may all ready know i. Also I'm pulling all this from the lore of each champion. In the second story, the targonians use his powers to seal a void rift. Though this is seemingly not much of a big deal, I will bring it up later. The final thing is the solari trying to keep the lunari a secret or trying to remove them from history entirely. But, this is where we just start with our theory.
Seeing how the Solari act time and time again in the lore got me thinking. Just how many crimes did this group of people actually commit and how far has their reckless actions been felt within Runeterra? It couldn't be that far, could it? As I read through the countless hours of story this game has to offer us, I was quite surprised when I found out how far the proverbial dominoes fall just by a few simple actions on their part.
First, The solari first start out by praising the sun which isn't all that bad. the day Aurelion sol descends to the Targonians, this threatens their very belief that the sun is the point where life begins. So to prove their dominance, they enslave him as he ascends. During the void rip incident, they call him to seal the crack with some freshly made stars. This would work if it was properly fixed from the opposite side where there was the most damage (Unless you are Vel'koz or Malzahar who can open and shut rifts with ease.) What they had done by plugging one side is allowing pressure to build up. It's essentially a cork holding back a dam. What the Pantheon had him do was throw multiple rocks at the glass veil of reality and the void completely oblivious/ununderstanding of the consequences.
In this case, it allowed the void hole to be plugged causing the void to seek the next point of least resistance. It shifted down from the middle of Runeterra, to the left, and right. We know that this is where the void cracks are due to where the void creatures and voidborn emerge. Kog'maw appeared in the dessert and ate everything he came across including a tribe of wandering nomads. Vel'koz emerged by Urtistan, the home of Zilean which is in the desert. Kha'zix appeared by the Kumungu Jungle with very little food source like you would find in a dessert, so he went into the jungle. Rek'sai appeared in the dessert leading the Xer'sai. Malzahar lived in the dessert as a seer nomad when he came across Icathia and became voidborn due to a powerful void presence. Kassadin came across Icathia, but had an opposite effect on him and almost the same can be said for Kai'sa, who also emerged from the desert. The only void creature/voidborn that has no direct ties to anywhere is cho'gath, but as we are seeing that everyone appears south of the great barrier, it is assumed that he came from the south as well.
The portal in the Shuriman Dessert though didn't appear until after the void scar at Mount Targon was forcibly closed. To save themselves the headache of void creatures, the Solari pushed their problems onto another group. By plugging the gap, they caused the void to punch through the next highly charged point of spirit energy, which would be Shurima due to all the ascending, and thus, bringing problems upon all of Runeterra instead of just around Mount Targon where the spirits may have been able to combat and stop such monstrosities. Instead, they would rather not have been bothered by it.
Now this next part is a bit harder to explain. Due to the Solari's want of power and control, the Solari tried removing the concept of the Lunari from history. They rushed the prophecy that there is going to be a daughter of targon who will make peace in the heavens by selecting Leona. They interrupted a trial to determine Leonas fate to drop this title upon her. They then escort her up the hill and taught her the Solaris ways. When diana found and donned the Lunari armor, coming back with truth of solari and lunari working together, it didn't fit their want for full power. if the lunari was there, it would be another group looking over them, interfering with their work, a conflict in beliefs, and it would mean they where wrong in choosing Leona for the position. If we come from these points, it makes sense. Thing is, in wanting so much power and wanted to save face, they hurt the rest of the planet including reality.
So in taking a step back we can see their crimes are starting to step out in the open. They enslaved the star forger, committed genocide on a rival group, misuse the power of Aurelion sol, on top of numerous problems across runeterra along with hundreds of deaths due to void creatures. Thing is we know for a fact that those aren't all the void cracks. Let us go to the bottom of the ocean, to the marai tribe. As we learn there are terrors that haunt the deep and the only way to fend them off is to go into the abyss and pull an abysal pearl to take to the shore for a moon stone to send the creatures back, as dictated by the trial of the Tidecaller. Now, if we look at the comic connected to nami, the selected tidecaller descended into the abyss and was found with some unnatural changes, like a third eye, glowing purple, and talking about how the void can be a safe haven. After escaping the newly voided tidecaller, she takes on the mantle with the void pearl in hand and ascends to the surface looking for someone to trade the void pearl for a moon stone. The only people to have any connection to the moon is Soraka and Diana with Diana a bigger probability of the person she was to meet because the person with the Lunari armor was suppose to have a tales to perform as we see in the lore that is written in Dianas and Leonas stories. Because Diana never went on her half of the mission, the moon stone was never delivered to the Marai, which depended on the stone for, not just the safety of their people, but for the whole ocean as well. Thus, we have another place the Solari caused a problem for because of recklessness. Not to mention Fizz's tribe which mysteriously vanished and Nautilus who was pulled underwater due to a black ooze that changed him. Even Bilgewater is constantly under treat from the depths which seems to take a lot of its roots from the void.
So the crimes of the solari are as follows: the endangerment of the marai/probable extinction, the disappearance of Fizz's people, multiple void fractions south of runeterra(No recorded void creatures north of mount Targon, this even reaches all the way to Bilgewater), the elimination of the Lunari, the deformation of Nautilus, the endangerment of Bridgewater, shurima, and kimungu jungle, and the unjust imprisonment of Aurelion sol.
Now that the crimes are out of the way, it's time we focus on an interesting thing in each area. Mount targon is known for being a gateway between the gods of mount targon, namely, Pantheon, the spirits within Diana and Leona, Taric, and Zoe. Now Bilgewater has a big religion based off of Nagakaborous. Thus we return to the desert one more time. Shurima is drenched with spirit energy directly from Azir, Nasus, Renekton, and Xerath all ascending. Perhaps there is some connection between the actual solid religions of runeterra and the void cracks. Maybe the void preys upon these places because of the spiritual energy? Who knows. That's a theory for another time with much needed information.