This gamemode is like FFA, but with a teensy change to the rules. Once you are past level 15, the game will automatically give you a tier 2 class. However, don't get too comfortable with your new class, because it will be changed every 5 minutes along with everyone on your server. This continues past level 30 with random tier 3 classes and so on. Make sure you know your tank's strengths and weaknesses, because this gamemode will push your diep.io knowledge to the limit.
P.S - Make sure you balance out your upgrades
P.P.S - The smasher and landmine will not give you access to the upgrade extensions
Hope you liked the idea, let me know if you have any questions!