Sigh, this again.
Jax. Jax is the strongest champion Lore wise (and game wise at that).
You have to realise something... You can be immortal, you can be a God, you can kill people on sight, or 1 shot the world, Jax is UNDEFEATED! You being immortal and stuff won't matter to Jax, he will defeat you!
I don't know if you people actually read Jax's lore or what but he is definatly NOT what he seems. He's not just a "physical fighter", he didn't win all those fights just because he's good at using a "weapon". It's clear he's using some sort of hidden magic or energy or something.
My theory always was that he's a being made of pure energy. Those "eyes" are not "eyes" they are just holes and the light coming out of them is what Jax is composed off all the way. He has no physical form (only champ in the league who can dodge, surprise, surprise), so he cannot be attacked.
The way it looks he's the strongest physical fighter, hence the weapon restrictions, which don't affect him at all. For that to work he would have to be the strongest macial being and the whole weapon is just a trick to stop people asking questions. (If you take a good look as his animation during his 3rd hit on R, he actually hits you with the hilt of his weapon, which creates a rift in the animation). Mix that with the fact that he's pure energy, undefeated, only champ to get restrictions in the league and the champ with the fastest league judgement (took one second), you get an unstoppable winning machine.
People stop right away when they hear the word God, like Kayle. Jax is ABOVE gods. Get that straight, don't apply real life logic here. Even if you're immortal, and you're at full strenght and you fight Jax, Jax will win! It doesn't matter you command armies, or can one shot the planet, Jax will win. For whatever you bring to the table, Jax will win. It's stated in the lore.
PS: I don't think Jax is Ashram, it would be too easy.