Skills

Most cards only carry one skill. Some special cards can have two. There are various different types of skills, and most of them can be upgraded.

Skill Upgrading
A card's first skill can be upgraded by using Rare Medals on the upgrade screen with the following costs:

Archwitch damage-multiplier skills are upgraded by evolving the card to its max evolution stage.

Witch Hunt cannot be upgraded.

Skill Types
Below are all the different skills in the game. Take note that powerful skills are sometimes limited in the number of times they can activate (i.e. "proc") in a single battle. You can check a card's respective page for info regarding their skills and proc limits.

ATK Up
Boosts the ATK stat of a single card, whole unit, or cards of a specific element. Extremely useful against Archwitches. Usually limited in the number of times they can activate.
 * Category:ATK Up (Single)
 * Category:ATK Up (Team)
 * Category:ATK Up (Passion)
 * Category:ATK Up (Cool)
 * Category:ATK Up (Light)
 * Category:ATK Up (Dark)

ATK Down
Lowers the ATK stat of the enemy. Useful in conjunction with healers if your unit isn't strong enough to defeat Archwitches quickly.
 * Category:ATK Down (All)

DEF Up
Boosts the defense stat of a single card or whole unit. Provides very little effect.
 * Category:DEF Up (Single)
 * Category:DEF Up (Team)

DEF Down
Lowers the defense stat of the enemy. Provides very little effect.
 * Category:DEF Down (Single)
 * Category:DEF Down (All)

Healing
Heals a single card or your entire unit. Useful in conjunction with lowering the enemy's ATK if your unit isn't strong enough to defeat Archwitches quickly. Sometimes limited in the number of times they can activate.
 * Category:Heal (Single)
 * Category:Heal (Team)

Resurrection
Revives a defeated card.
 * Category:Resurrect

Damage Dealing
Deals damage to a single enemy or all enemies. Skills that damage all enemies are very useful in duels and campaign battles.
 * Category:Deal DMG (Single)
 * Category:Deal DMG (All)

Critical Hit
Deals approximately 12x-15x damage to a single enemy or all enemies. Extremely useful against Archwitches. Usually limited in the number of times they can activate.
 * Category:Critical DMG (Single)
 * Category:Critical DMG (All)

Suck Damage
Deals damage to the enemy in addition to healing the user based on damage dealt.
 * Category:Suck Damage

Turn Skip
Skips a number of enemy turns. Usually limited in the number of times they can activate.
 * Category:Turn Skip

Autoskill
Provides a passive stat boost. They are always active throughout the battle.
 * Category:Autoskill (ATK)
 * Category:Autoskill (DEF)
 * Category:Autoskill (EXP)

Reward Receiving
Guarantees a reward drop after the battle.
 * Category:Receive Rewards

Gold Conversion
Deals damage to the enemy in addition to providing Gold based on damage dealt. Only works in Campaign battles.
 * Category:Gold Conversion

Witch Hunt
Provides an approximate 50% damage boost against Archwitches.
 * Category:Witch Hunt

Archwitch 2x/3x, 5x/7x, 10x/15x Damage
Provides a massive damage boost against Archwitches. Cards with this skill are introduced every event, and the skill is active with those cards only during their respective events.