Upgrade

Upgrading (sometimes referred to as "Fusion") allows you to level up your cards. This is essential to maximizing the potential of your unit. During fusion, you can select up to 10 material cards in addition to Arcanas. There is also a chance of a Great Success from occurring, which doubles the amount of experience given. You can guarantee the occurrence of a Great Success by using Arcana's Blessing and even combine it with Arcana Training for a total bonus of quadruple experience.

Providing Experience
Among all, Lvl27 Slime is the most commonly used card in upgrading other cards.

The experience given from various sources are as follows:

General Cards

 * N-card: Lvl1 gives 100 exp, Lvl30 gives 2288 exp
 * HN-card: Lvl1 gives 150 exp, Lvl40 gives 7128 exp
 * R-card: Lvl1 gives 200 exp, Lvl40 gives 9504 exp
 * HR-card: Lvl1 gives 300 exp, Lvl50 gives 28791 exp
 * SR-card: Lvl1 gives 4000 exp, lvl36 gives 146184 exp, Lvl50 gives 383880 exp
 * HSR-card: Lvl1 gives 6000 exp, lvl35 gives 210671 exp, Lvl60 gives MAX exp

Specific Cards

 * N Gold Girl: Lvl1 gives 200 exp, Lvl30 gives 2388 exp
 * N Slime: Lvl1 gives 1000 exp, Lvl27 gives 9601 exp, Lvl30 gives 11942 exp, see Slime Experience for a full list
 * R Metal Slime: Lvl1 gives 3000 exp, Lvl40 gives 72783 exp
 * SR Slime Queen: Lvl1 gives 45000 exp, Lvl50 gives MAX exp
 * HSR Slime Queen: Lvl1 gives 90000 exp, Lvl60 gives MAX exp

Battles

 * Lvl100 R Archwitch gives 600 exp
 * Lvl200 SR Archwitch gives 1200 exp
 * Lvl250 SR Archwitch gives 1500 exp
 * Lvl300 SR Fantasy Archwitch gives 1800 exp
 * Lvl300 UR Fantasy Archwitch gives 3000 exp
 * Lvl300 HUR Fantasy Archwitch gives 3600 exp
 * Lvl400 UR Fantasy Archwitch gives 4000 exp

If upgrading a card using battles, you can increase the amount of experience per battle by using Autoskill (EXP) cards in your attack unit.

For example, if a comrade or Alliance member can send you a low HP FAW, you can max level 4 Slimes using a team of 4 Slimes and 1 Fortuna with a single FAW (4000exp x 2.4 = 9600 exp : level 32)