The illogical function of Pantheon's W Aegis of Zeonia

This is a question about Pantheon's ability when he has a Renekton as his lane opponent. My English is still not good so forgive my mistake. Panth's W can totally blocks the damage and stun come from Rene's W Ruthless Predator, this doesn't make any sense, at least the descriptions of these abilities show nothing about it. Compare with Jax's E Counter Strike, both Panth's W and Jax's E can block basic attack, and the ability descriptions say so, but now the question is that Jax's E cannot block Rene's W, neither the damage nor the stun, so we can't see Rene's W as basic attack, but meanwhile, Panth's W can totally block both, so does that mean Rene's W is a basic attack? This is a paradox. Also, Panth's W can block Iceborn's passive but Jax's E cannot (If I am right).