The arena was a very simple system like any other the twins saw back in the Lisan Universe. In the end, even advanced societies can't help but try their own strength against similar opponents. This is the cultivation world for you.
"Simply put, you register in the arena network system and place how many Spiritual Stones you want to bet," the worker there explained. "The arena system will then select an opponent with similar cultivation to be your adversary. Of course, it is up to the other cultivators of our Gondel Clan to look into your information and then accept to fight with you. At the same time, you can check who decided to accept your challenge and see if it is fair or not. In case you think it is a lost cause, you can also refuse to accept that challenger."