The DigiDestined and their partners are wandering through the desert and they are getting very tired and are also starting to loose hope. Tai tells them that everything will be okay because they have a crest. He starts to pressure Agumon into Digivolving. Tai wonders how Agumon will be able to Digivolve again. Izzy explains that if it works the same way as before, Agumon will need to have lots of energy from food and Tai will need to be in danger. Tai then starts stuffing all of the food that the group has into Agumon despite him being full. Everyone else begins to worry about Agumon and also Tai's personality changing. Sora recalls that when they used to play for the same soccer team, Tai did everything he could to help the team. Suddenly, Joe's tag begins to glow. As they wonder where the crest is, Tai sees something out in the distance. Joe heads there, thinking it must be where his crest is when he trips over a cable buried in the sand. Meanwhile, Etemon's computer tells him that the kids are near the Colosseum. He then calls one of his Gazimon who is stationed there to be ready for them.
The DigiDestined and their partners arrive at the Colosseum but are confused that it has soccer goals. Tai tells everyone to split up and look for Joe's crest but Agumon falls over needing to rest from all the food Tai made him eat. Joe tells everyone to rest while he and Gomamon look but Tai follows to look too. A soccer ball then rolls over to the group and Sora organizes a game for them all. Tai angrily kicks the ball away and yells at everyone for playing a game now. As Joe's tag starts to glow even brighter, Etemon appears on the jumbotron. Everyone runs to the soccer goal where they get trapped except for Agumon who didn't make it there in time. Tentomon tries to escape by flying through the net but it zaps him so they can't get out. Etemon says that he can't be there himself but he has someone else coming for him.
Suddenly, another Greymon appears and begins to rampage around the Colosseum. Agumon Digivolves into his own Greymon to fight him. Unfortunately, Tai's Greymon is losing. Everyone knows that he can only win if he Digivolves again. Tai starts to yell at him. The two Digimon continue to fight but Tai's Greymon is running out of strength from eating too much. This just makes Tai even more angry. Everyone then starts to tunnel out of the goal they are in but there is a huge stone in the way. It turns out to be Joe's Crest of Reliability and the group escapes through a tunnel.
Tai realizes that Greymon will not Digivolve by himself and he need to put himself in danger to make him do it. Tai then runs out into the middle of the Colosseum and tries to get the other Greymon's attention. Biyomon and Gabumon Digivolve to try to help but Tai is still yelling for Greymon to Digivolve too. Suddenly, Tai's crest and Digivice begin to glow and Greymon Dark Digivolves to SkullGreymon. Everyone is very worried and confused about this huge Digimon that Agumon became. SkullGreymon easily destroys Greymon but he then turns on Tai and his friends too. Birdramon, Garurumon and Kabuterimon, who have joined in, can do nothing to stop the ultimate. He then continues on his rampage but soon runs out of energy and becomes Koromon.
Koromon is very sorry for all of the damage he caused but everyone says it is okay and not his fault. Tai takes responsibility saying that because he had a crest, he thought it meant that he had to fight by himself. Tai apologizes to everyone, especially Koromon, who forgives him.