You can use your Hero's skills during battles. Skill effects can be different, depending on each type of your Hero's weapons. Once a skill is used, you can use it again after a cooldown period. You can only equip or use up to three active skills. You can also create combo skills to attack with up to three skills consecutively. Create unique combo skills equipping up to three skills to combo slots and using them consecutively in a battle. The cooldown period for equipped combo skills is 50% longer than the original skill. Slots will be expanded automatically when you reach to certain levels or by spending gems.