Using

Roan's mouth twitched in response to Rean's words. "Then what? Is Ariel there too? Ursula perhaps? Go to hell!"

Rean laughed as he replied, "Hahaha! You say that, but you do know your things, don't you?"

"Hmph!" Roan snorted in response but didn't answer.

As for Kentucky and Red, they had no idea what Rean and Roan were talking about. Well, Rean and Roan didn't answer their questions anyway.

Soon after, Rean's group made their way into the Demon Beast Underwater City. Sure enough, the city was full of high-level Sea Demon Beasts. With Rean's Spiritual Sense bending skill active, there was no lack of Stage Six and Seven Demon Beasts there. Those at Stage Eight were also present. 

However, above all that, Rean could feel the Spiritual Sense coming from a Stage Nine Demon Beast, a stage which was no weaker than what Phex or Xaon had achieved.