Guide to Stamps

I have been grinding stamps a lot and I think I have figured out how their main and secondary stats work. Here is all my findings so far:

There are 3 stamps. Their names change based on the set so I will use their main stats to distinguish them.

Each 5 star slot has 2 main stats, but the first main stat is always fized. By their order in the menu, its flat atk, flat def and flat def.

Here are the available 2nd main stats for each stamp type:

Flat ATK Stamp: %ATK, %HP, Flat HP, %DEF, Flat DEF, Slash Damage, Spirit Damage, Strike Damage, Thrust Damage

Flat DEF Stamp: %ATK, Flat ATK, %HP, Flat HP, %DEF, Crit Rate, Crit Damage

Flat HP Stamp: %ATK, Flat ATK, %HP, %DEF, Flat DEF, Ultimate Charge Rate, Ailment Damage

Now for the secondary stats and how they work. These do not differ from stamp to stamp and they can be the same as a main stat on the same stamp. Each 5 star stamp has 4 different secondary stat and one of them increases each time you ascend the stamp.

Here are the list of available secondary stats: %ATK, Flat ATK, %HP, Flat HP, %DEF, Flat DEF, Crit Rate, Crit Damage, Ultimate Charge Rate, Ailment Damage