Side Quest: The Forbidden Chest
Recommended Level: 47

Preparation
At your current level, you don't need a lot of preparation. You can even beat the boss without it calling "External Darkness".
- Recommended Party: Leo, Ez, Cheryl, Zinikr. Tan is also a good candidate.
- Equip Onyx XL, Onyx L, Diamond XL and Diamond L on everyone.
Steal:
- (I-01) Elixir
Strategy:
- Just like its counterpart you previously fought the "External Darkness". It's gonna come close and go afar every 3 turns.
- Ez alone as a support and healer should be enough while Leo and Cheryl go full offensive.
- Leo applies debuffs "Attack Down" and "Defense Down".
- If you prolong the battle, it'll summon its counterpart "External Darkness". Both of them will take turn switching back and forth. This is when you should switch between Cheryl (Darkness Strike) and Zinikr (Brilliance Strike) depending on who is in front.
Reward:
- (I-02) Tyrfing