Raikou has arrived in the Legendary Arena in Pokémon Masters EX! You can complete the designated missions to get exclusive medals!

Legendary Arena Raikou

Legendary Arena Raikou Available Now! Legendary Arena Raikou is a brand new battle area that has just been added today! You can complete the related missions to earn Medals that can only be obtained here! Plus, event missions have been added for a limited time! You can complete higher difficulty missions to get Gems!

Legendary Arena

The Legendary Arena is a special battle area where you can form multiple teams and take on the challenge using a set number of sync pairs. You can complete the related missions to earn Medals that can only be obtained here!

Important

• To attempt Legendary Arena missions, you must have completed Main Story Chapter 2: Defeat Team Break! (Normal) in single-player.
• The added limited-time event missions do not count toward the completion requirements for Legendary Arena Mission Completion Rewards.
• All mission completion rewards for the added limited-time event missions must be claimed within three days of the mission period ending.
• The time period and featured content are subject to change without notice.

Source: https://pokemonmasters-game.com/en-US/announcements/Event_5060_3W_1