Gaderong

"Do you want to try your luck in the Celestial Arena Come on in and test your skills in the Celestial Arena! Even if you get knocked down, you can get right back up again! Herd the monsters together and take them out all at once!"

is the gatekeeper for Celestial Arena and is a solo dungeon that becomes available for entry to players at level 65 and costs 70 Adventure Coins. It was added in Ninja patch in April/May 2016.

Quotes
"Hello! I am Gaderong, your guide to the Celestial Arena! The arena presents challenging trails at each stage! If you'd like, I can send you there right now."