You must acquire lots of cards to experiment with evolution. You can purchase cards or win them from matches. No matter how low the tier, every card you obtain will be useful. Sacrifice low tier cards to boost your top tier cards. After boosting a card, its stats will increase. Use boosts and evolution to make a strong team. Farm previously completed missions to get a chance to get cards to boost your AP or BP levels.
Evolution
An evolution icon will appear when all cards of the same icon are found. Keep track of evolvable cards because you can trade them. Experimenting is important for effective evolution and a chance to get powerful cards. Each card has its own combination of material cards that are required to make the exact result for a specific card. After completing the combination, its recipe will now appear on the evolution screen. From here experimenting with different combinations will give possibilities to get a new card.