The premium dungeon is a daily dungeon for people who have premium membership. Completing the dungeon will give you 5 premium tokens that you can use to spin the wheel in Queenstown. One spin consumes 5 tokens. You can get all 5 tokens even if you choose your character and then AFK until the end, but you will want to actually kill the enemies that spawn, because you will get mesos per enemy you kill at the end. By the end of it, you can get around 250,000 Mesos or more.