In the conversation with Tang Wei, he says “you are a possessor of Chaos Origin Physique, someone with unparalleled gift to study the Dao”, as he is who he is, we can assume that his statement is a fact. In the conversation with Butterfly, she not only mentions that MC has god potential, she also says that if he doesn't die, MC will reach god level in record time.And what exactly does Ruo's physique do? I don't think it has been fully mentioned, but as far as I understood, the only thing our physique had over his was the limit, not the learning ability.
As for Ruo's physique (still unnamed, but Butterfly says he's a Sword Child), as far as has been said, he's attracted to the sword and instinctively understands its Dao, he's a Dao Child, he's protected and loved by karma and the Heavens (Nicky). It is also said that his growth is irrational and that with a sword in hand, his techniques are simply more powerful.