[Rush] is a mode where you can fight several enemy groups consecutively.
Groups are divided into WAVEs, and when you defeat all enemies, the next WAVE will appear.
If you defeat all the enemies within the FINAL WAVE, you will clear the Rush, and you'll gain clear rewards.
The Rank you can challenge in Rush will be decided by the Technology Level.
If the Technology Level is over 100, it is possible to lower the challenge rank to 100 at the lowest.
If you give up during a Rush challenge, you will only obtain the rewards from defeated enemies.
If all battle members are KO'd, the Rush challenge will end, and you will not obtain any rewards.