Actually ,it's because some stuff requires "Cyans" to be bought.Cyan is the money which can be traded with real money(euros).
For the moment,when you create a character with this stuff,the game crashes.
Once the character created,you are free to buy (or not) cyans to change your character as you wish!
It's optionnal ,excepted potions which give more life/mana,stuff is just for decoration.
I hope you will understand me
Have fun on Dungeon Party !