Why does everybody expecting Mokuba? There are far better options: Noah - DL is a digital world, just like Noah's. He could have Yamata dragon as signature card and his rewards could be Yata Garasu, Hi No Kagutchi and list goes on.
Yata Garasu will never be a card players can use. In some of the Yu-Gi-Oh! Games for game boy advance it was a banned card. Banned as in you can't even use 1 copy of the card. That was understandable since the card can stop you from drawing for the rest of the duel.
where you start with only 4 cards, there is a fair chance you don't have a monster card at all when you start or only have high level monsters as a starting hand. Get stopped from drawing then and you're 100% going to lose
WeegeeKing
In a game like DL
