1. Start Challenge

1) Fuhrer's Secret Base is on the top left corner of special operation map.

2) Only corps leader or R3 member can start it.

3) There are several stages which need to be completed in sequence.

4) Each challenge lasts for a certain period of time. The next challenge can only be started after the previous one ends.

2. Join Challenge

1) After it's opened, corps members can start their attacks.

2) Each member has a limited amount of attack chances each round. Please use them carefully.

3) After each battle, the remaining state of the stronghold is saved and other members can continue to attack.

3. Rewards

Rewards are sent as corps gifts after a stronghold is destroyed.