Talent vs Effort
Ryu didn't know how long he slept, but when he awoke, he felt refreshed. This was no doubt related to the world that he had fallen asleep in. It could be said that the accommodations for Core Disciples were more excellent than any Sect that Ryu had ever seen before. Even the Martial Gods and their courtyards couldn't hold a candle.
Granted, he hadn't been to the true core of the Martial God's territory. But he felt that it was pretty safe to assume that it was still inferior to this.
It had to be remembered that Ailsa was a Feng Shui master and a Herbologist herself. The only reason that she couldn't deal with the situation herself was because she was stuck defending her Holy World. Also, even if she had, with her strength, she couldn't enter the Perfect Grade Holy World to begin with.
It could be said that Ryu was the only one that could do what he did.