How many challenges I can purchase?

There is no limit to the number of challenges users can purchase, whether they are of the same type or different types. However, during the Trader Stage, only one ongoing challenge of the same type is allowed at a time.

For example: If User A purchases 1 Base Challenge and 2 Advanced Challenges, only 1 Base Challenge and 1 Advanced Challenge can enter the Trader Stage, as only one challenge of the same type is permitted in the Trader Stage.