Colosseum

Colosseum will be unlocked after you reach Royal Capital Grandshelt in the story. It can be accessed from the home screen.

Colosseum is a game mode that pitches you against different enemies. The battles fought here starts easy but get considerably harder once you hit higher rank. The battle is identical to the one found in the story dungeons, with the exception of these limitations:
 * Consumable items can't be used
 * Lapis revival can't be used
 * Friend unit can't be used
 * Actions don't count towards trophy achievement, except for colosseum achievements

You have to accumulate 1000 colosseum points before you can fight the round's boss. Each successful battle adds 100 points while an unsuccessful battle subtracts 50 points. Losing in a boss battle does not subtract any points. After defeating the boss for the first time, a special reward is given and you advance to the next round. A different reward is given for every subsequent victory.

Colosseum shares the same orb system with Arena. An orb will be consumed to enter a battle. You can have up to 10 orbs simultaneously and they recharge at a rate of 1 per hour from the moment you use one. All 10 orbs are automatically replenished when you rank up. It takes a minimum of 825 orbs to complete all rounds of the Colosseum plus 80 more to craft the Blood Sword.

To select your Colosseum party, you can go to the Manage Party button that appears before entering any Colosseum battle. The chosen party will always be your default Colosseum party.