The Story of Jax
Nobody knows what Jax is. He claims to be a fighter from a city-state that no longer exists, which is either metaphorical or literally true in ways that cannot be verified. He fights with a lamppost he chose as a weapon because his actual weapons were too dangerous for organized combat — this is either humility or provocation, and the distinction matters less than the result, which is that he is winning regardless. He has been winning for a very long time.
He exists in Runeterra's margins, entering competitions and conflicts to measure himself against whatever the current age produces, finding the result consistently disappointing. The challengers who reach him are genuine: he does not mock the effort. He simply has not found anyone who makes him fight at what he estimates is his full capacity, and this is a problem that is both a practical disappointment and an existential one. He was built for a war that may not happen, and the waiting has been very long.
He is waiting for the Void. This is what most of the serious theories converge on: something made Jax, or shaped Jax, or Jax made himself, in anticipation of a threat that requires a specific kind of weapon. He tests himself against Runeterra's best fighters not for glory but to know the state of the available resistance. He has not yet found a reason to be optimistic. He keeps looking, because the alternative is deciding the answer before all the evidence is in.