I know one guy that wil team up with you and his name is Elgio where you can find him is before the house of blister and then on the left are standing two guys en the right guy is Elgio.

When you beat him he will ask you if he can team up with you.

His specialties are that he has many cards that damages the opponent so he is really usefull and I won with him but you must not have your Prime Material dragon in your deck becuase his effect will let the damage will heal him so don't use the dragen.

If you don't find any partner for the tournament you must go to blisters house but not go inside but you must duel elgio that stands for the house wich another guy but fight with elgio and win and he asks you to be your partner and than go to the stadium and then you can enter the tournament.

And for the ones who want to now the first opponents are very simple. But in the semi finals you must duel with blister and bolt(the guy from the jail) but they aren't very difficult and in the finals you must duel with the Twin Celebs (Leo and Luna)