Ryu's speed caused Empana's own gaze to change somewhat, but he realized that Ryu hadn't accelerated, he was still flying at the same speed. Rather, this seemed to be a good idea, if they disappeared into a tunnel now, it would be easier to lose Norrian. After all, it would be hard to tell which tunnel they had entered from.
What Empana didn't know was that it was trivial for a Ruin Master to find out such a thing. Even the worse, most incompetent Ruin Masters could track a location living beings had passed through recently. However, Empana wasn't a Ruin Master, so how could he know this? If it was possible to avoid detection like this, then Ryu wouldn't be so worried about others following his actions and finding out he could do something they couldn't.
The group rushed into the tunnel and vanished.
Dozens of minutes later, the Exo Demon Race rushed out after them.