Natural
As Ryu moved, his mind flashed with several thoughts. He knew that Primus likely already knew where he was, and he also knew that even though he had yet to show himself, he was likely only a thought away. He didn't believe that the barrier between the Sixth and Seventh Heavens would be something that would stall Primus.
He had to lose him.
The reason for this was simple. As amazing as it sounded to drag a Half Step Dao God on adventures and have a perfect sheen of protection, there were several issues with this.
For one, these areas weren't places that even Dao Gods could ignore. Even a Dao God would have to be cautious against something like Infinity Mist, especially if it appeared in large quantities, let alone a Half Step Dao God.
That said, if Ryu was to say that he was caring for Primus' safety, who would even believe him? Of course this was ridiculous and he never had any intentions of minding such a thing. The real issues were what came next.