If you go to the Void page in Universe, it says that the Void is a place where a long-finished war took place. A lot of people are talking about how Jax is from Icathia, but what if he is actually just a surviving soldier from that war?
I think the war mentioned on the void page is actually the one between Icathia and Shurima,since it never says that the war was within the void. So yeah if Jax is a surviving icathian,then he likely participated in that war(similar to how Renekton actually fought in it)
Jax isn't from the Void, he's from Icathia. Icathia was a human city-state that was at war with Azir's empire. They rent open a portal to the Void in a last-ditch effort to drive off the Ascended and their armies, but it ended about as poorly as one might expect. Jax was apparently exposed to the Void and changed by it, sorta like Kassadin. As a result, he's now an immortal bad-ass looking for a partner to help him kick Voidborn in the teeth.
Best part is, Fiora and Jax fought. Whoot!
