Mastery

Mastery is the usage of a card. When a card is fully mastered, it will gain an increase in stats to that card, if you have one of the same cards, mastery will not be maxed out on that card as it happens only to a singular card.

To master a card, assigning it as your primary card while doing missions will more often than not give you an increase in mastery according to the energy used in your chosen mission. For example, if you are doing Operation 11 you will gain 10 mastery increase.

Cards in your attack deck will also gain an increase ranging from 1-5 depending on the level of your opponent. However this only happens in attack decks you use. If your opponent is lower than you in level, you will either get no increase or +1 increase, opponent's with the same level will give you a +3 increase and those above you will give you either a +4 or +5 increase. Take note that this will only happen if you win the battle.

There have been occurrences where players have had cards that are neither in attack decks or have been assigned as the primary card gain mastery.