When I am banning I don't ban Jax and get so much shit for it. But when they first Jax and I pick Pantheon to fight him I am yet to lose. I destroy Jax and ult gank all my lanes. Jax is never a threat to me... but if I am not banning he is always a first ban pick. Why?
Let's see... He can still deal frightening amounts of mixed-damage burst while building armor, MR, and health, AND he has an on-demand temporary immunity to auto-attacks followed by a close-range stun - which he can bring to you by Leaping, even if you know how to get out of range.
The damage is scary enough when you go against him, but he's also very resilient in teamfights.
Maybe Panth counters Jax somehow? It might be just your playstyle, as well.
