to buy a rank up, you must spend a certain amount of DP.
Here are the prices:
Ojama Dorm Rank-Up: 200 DP
Kuriboh Dorm Rank-Up: 250 DP
F.G.D Dorm Rank Up: 300 DP
Crimson Dragon Squad Rank-Up: 400 DP
You cannot buy your way into the Creator Gods. The only way to get into that is to win any of the many tounaments we will have.