You can assign a second unit to your selected main unit to increase your HP and ATK, and combine skills to battle.
- Go to Edit Party to choose your main unit and armament
- Select a second unit to be assigned from the small unit window at the bottom of the armament selection screen.
- Go to the Mana Board of the second unit to check your abilities and see whether they can be applied when assigning seconds.
You can also check the details of a unit from the unit list at the top of the Units menu.
Select the skill [Preview] at the bottom of the Unit Details to watch a unit's skill animation, compare each unit's skills and abilities, and assign seconds strategically.