Could the Void be linked to Ekko and the "Incident"?
[[TL;DR at the bottom]]
As far as we know, Ekko, Vi, Jinx and the unknown boy from the mural were part of the same Zaunite gang until something happened which led to Vi's amnesia, Jinx turning mad and the apparent death of the boy. Considering that Ekko is trying to "fix" the past but cannot, for example, revive or protect the fourth member of their gang from whatever happened to him I assume his time manipulation is nowhere close to Zilean's disease and, if his trailer is anything to go by, seems to only affect the most recent actions done (No "true" time travel, just a short rewind).
Now let's dig a bit in the older lore:

" Despite its name, the Void is not an empty place, but rather the home of unspeakable things, horrors not meant for minds of men. Though such knowledge is lost in modern times, there are those who have unwittingly discovered what lies beyond, and they have been unable to turn away. Kassadin is such a creature. He was once a man forced to look upon the face of the Void and forever changed by what he saw."
Kassadin was changed quite a bit from his Void exposure. He remained sane, so to speak, but with his body disfigured and his newfound Void-based powers he was no longer a normal man either.

" His eyes, seeing what others cannot, and what none should, were filled with the essence of the Void. His once shifting visions of the future were replaced with the immutable promise of Valoran beset by creatures of the Void."
Malzahar, a powerful seer, was driven mad by the Void for he could listen to the beings living there despite them existing in another dimension.
Reading the lore of both Champions makes it clear that the Void isn't just another plane of existence but - similar to the Lovecraftian horrors it's inspired by - is able to warp reality itself. Malzahar went mad from the realization of what the Void is. Kassadin seems to have suffered even more by it, maybe by direct exposure to the Void's elements.
Now both Kassadin and Malzahar are no normal mortals. Both of them sought knowledge and power for different purposes and both of them were quite powerful before their "corruption" in their own way. In a way, the Void amplified their innate powers and magic.
But what about "normal" humans? What would happen to someone exposed to the Void who does not have raw magic power at his/her command or someone who, despite fearing the Void, is simply too young or to naive to fully comprehend what happened to them?

Now, there is an interesting and really old tidbit of information, straight from the Journal of Justice Volume 14:
"League Champion Kassadin is on the run after a failed attempt to prevent a sacrificial ritual, resulting in a major blackout within Zaun. According to witnesses, he discharged Void energy in an attempt to save a young woman from being sacrificed at the hands of fellow League Champion Malzahar. The energy was sucked into a hexvein conduit feeding into the nexus powering the southern district, causing extensive damage that will take Zaunite techmaturgical crews several days to repair."
Now, we don't know WHEN Kassadin and Malzahar were corrupted but we do know that Malzahar at least once sacrificed people from Zaun to the Void (Kassadin daughter in this instance) and that Zaun houses a group of Void cultists as well.
Now, with these information at hand, could It mean that the "Incident" which lead to Ekko's gang dissolving was a Void ritual they unknowingly crashed into?
The Void has weird effects as seen in the cases of Kassadin and Malzahar and these changes come with the level of exposure to the Void. Considering this, it could be possible that
, in an attempt to save the group, took a full blast of Void-magic which in return cracked her sanity and drove her mad. Much in the same way,
could have taken a weaker blow and only lost her memories. The boy from the mural might have been killed, displaced or taken by the Void. Ekko, as he seems to be youngest of the group, survived without major injuries but in return might have gained something in form of his time-based powers.
But why should the Void grant a mere boy such a gift? Especially such a powerful one more fitting for high ranking members like Malzahar?
Because it was an accident.
Ekko has interactions with many champions, Zaunite and "Pilties" first and foremost. The former are members of his city state, the latter are Zaun's rivals, similar to the Demacia/Noxus relationship. However, Ekko also interacts with
and, surprisingly,
.
I assume, that the cultists in Zaun tried to summon Vel'Koz into Runeterra or, at the very least, communicate with him as he seems to be the "smartest" Void creature. Another theory of mine would be that they captured Zilean and wanted to offer him to their Gods. (Vel'Koz is fascinated by Zilean and wants to interrogate him as he holds ultimate knowledge thanks to his disease).
What happened next is shrouded in mystery: Somehow the ritual failed. Maybe Kassadin intervened, Zilean himself successfully stopped them or the cultists did something wrong... or a group of meddling kids ruined everything?
If the Void is indeed at fault here it would explain why Ekko interacts with both Vel'Koz (The being who destroyed his "family") and Zilean (A mentor/Catalyst to rewind time far enough to prevent the Ritual in the first place).
But maybe I'm just crazy and reading too much into this @_@
Thoughts?
TL;DR:
Ekko, Jinx, Vi and blonde boy were part of the same street gang from Zaun. Street gang interrupted a Void ritual to summon Vel'Koz, getting exposed to Void magic in the process. Blonde boy died, Jinx went mad, Vi lost her memories and Ekko received timey-wimey powers. Ekko interacts with Vel'Koz because he is responsible for ******* up Ekko's gang. Ekko seeks Zilean to improve his time powers, use him to rewind time far enough to rewind all of this and to protect the old man from Vel'Koz.
Discuss!