So basically Urouge

>Went straight to the moon from Balloon terminal after pitying the strongest beast Kaido
>gained Lunarian powers
>Haki bloomed and whooped Enel's ass with his new invincibility powers and took his flying ship and learned moon history
>Flew HIS new ship the Ark Maxim into Marijoise to personally whoop Imu's ass after learning the lost history from the moon runes and take back the Red Line as home to Lunarians
>Realized Imu wasn't there and used his Lunarian flame powers to turn the island into a sea of flames then fucked off to find Imu
>Is now heading to Elbaf and will personally crash his ship straight into Imu's face and pick a fight with Imu
>Will tell Robin some of the lost history and hand over the Ark Maxim details to Franky
>Will take the Strawhats to Birkan atop Elbaf and have Luffy clear the lightning of his old home and become the final joiner once Franky updates the ship to fly as the pilot

Do you think he'll return after the flashback?

Are you fucking pussies ready for his return?

So basically Urouge is the biggest GigaChad in the series. He's currently on the moon fighting Enel. See to reach the moon the ancient sky people took balloons, it was foretold in the ancient ruins. Urouge's tan skin, massive body which is the middle size between Lunarian and Sky people, hints that he's a Lunarian hybrid. It was said that Birkan's strongest knight fought against Enel and lost, and coincidentally Enel showed up just recently despite being in his 50s.

So what would a Smiling Monk worship? The sun god of liberation that brings people smiles. He's definitely a Nika follower. He's currently fighting Enel on the moon after taking the balloon terminal up, will unlock his Lunarian powers and come back as Luffy's own Whitebeard, a rival and equal. A man with near invincible Lunarian flame powers, a fruit that turns damage into raw strength, and the Birkan martial arts which was elite enough to fuck up Luffy, Zoro, and Sanji during Skypiea. Urouge is the Lunarian we see in the Elbaf mural.

Urouge is THAT guy.