Arigora Colosseum (or PvP Arena or Arena). To access the UI, it is the Cultivation > Colosseum (Alt + J) as a shortcut.
There are three different types of modes:
Solo (Personal Matchmaking)
3v3 (Squad Matchmaking)
6v6 (Squad Matchmaking)
To enter personal matchmaking, you would need to speak to Arigora Agent Khroatis NPC and choose the Personal Matchmaking option that appears in the windows. Personal matchmaking matches you with other players who have queued up for solo, and put you in teams of 3 or 6.
A 3v3 squad can have up to five squad members and no duplicate classes are allowed. A 6v6 squad can have up to 10 squad members and can only have a maximum of two players of the same class. Players can join both a 3v3 and a 6v6 squad but will only receive the rewards for one; whichever has the highest score.
In the Colosseum, flyers, mounts and all kinds of Elixir are allowed. Genie's energy recover rate is reduced to 1/4. When a player is killed in the battle, they will stay in the battlefield as a ghost. They cannot attack others or receive any attacks. Any player who is disconnected before or during the battle will be counted as killed. Each battle can last a maximum of ten minutes.
Awards are given out Weekly and are calculated on the player's Squad Score. The reward is Arigora Coins which can be exchanged at Arigora Agent Khroatis.