Bosses will have clues as to when they are about to launch a big attack. This usually is in the form of a glow forming around them. Be prepared to use double jumps to get over attacks that involve them charging forward or launching a projectile.
Combos
Build large combos whenever possible by moving and using all of your skills. Because skills have short cooldowns, you can use them rapidly. Your Soul Arts gauge refills over time, and can be sped up by collecting souls dropped by your enemies. The higher your combo count when killing enemies, the more souls they will drop. It is made up of five different cards. When your Soul Arts gauge is full, you can hold down the button to play all of your cards out in one large combo. This will expend the entire meter, and is best used against a Boss or a large group of opponents. However, the Soul Arts combo can be stopped as desired by releasing the button in order to conserve soul energy. However, you will not be able to restart the Soul Arts combo again until the gauge is back to full.
Elements
There are nine different element types: Fairy, Beast, Human, Soldier, Demon, Dragon, God, Machine, and Abyss. If your Soul Arts cards match an enemy's type, your damage will be boosted. This is also indicated by blue numbers and lighting effects.
Soul Arts cards
Combine other Soul Art cards or Elemental Orbs with a base Soul Arts card to increase its level. Depending on what you fuse the base card with will create various bonuses. For example, fusing two of the exact same cards will result in double experience. Once a Soul Art card is at maximum level, you can evolve it by combining your base card with a card of the same type but at maximum level. This results in a higher rarity card. You can also fuse cards. Take three maximum level non-evolution cards and fuse them into one strong card that can evolve.