Yep, they finally gave him a name! After 2589455 years lol

His name is: Ōza Akaboshi

I thought... He is a protagonist too... Where's the Yu? wth...

Behold to the new king of duels!

Though... Here's the info for Ōza:

 Old comrade of the Four Duel Kings (no idea who they are?) - who is called the "Perfect Champion" - returns to the Satellite shop, Shoma and asks him for a duel, so they can become friends. 

Yuga and Luke/Rook can bring him water lol xD

He even beat Shoma Yusa lol xD