Champions must be leveled up in order to progress. Champions have ranks, each of which have ten levels. A two-star character has three ranks, allowing him or her to leveled up thirty times. Each time you level up ten times you will need a catalyst. By ranking up, you will increase a Champion's AP and HP and unlock new special attacks and increase the level of "specials", their passive abilities. Champions at maximum level can rank up to improve their stats. To rank up a Champion, you will need specified catalysts. Note. After ranking up, the tier (number of stars) will remain the same.