He is the 2th known person in the in-game world for his unbelievable luck at winning games. Max has a partner with him but his role in the story is unclear. He has encountered Dark Unknown in the past, the backstory is still unclear.
Luck, however luck does not grant things to appear out of no where (clean water from space). Its believed that the writer is granting him all the luck in every possible way. In a battle his hp and attack is 777 or 7777 making his hp and attacks only in the 7ths.