Upgrading
Characters, weapons, and summons can all be upgraded by absorbing materials to gain EXP and level up.
About Upgrading
- When upgrading weapons, using weapons of the same group as materials confers an EXP bonus when absorbed.
- For characters and summons, using weapons and summons of the same element confers an EXP bonus when absorbed.
- Once a weapon is fully upgraded to its max level cap, it can only absorb weapons that have skills.
- Duplicate copies of the weapon or summon you are currently upgrading can't be used as upgrade materials.
- Absorbed materials disappear after use.
Upgrading Weapon Skills
- Main article: Upgrading Weapon Skills
By using weapons with skills as materials, it's possible to level up the skill of another weapon through upgrades. Using a weapon without a skill will not level up the skill of another weapon.
Elemental Skill
- Main article: Elemental Skill
Elemental Skill (called "Upgrade Skills" in-game) represent your overall upgrade mastery. Each element has an upgrade skill and associated level, which can be viewed on the Profile screen from the menu. Upgrade skills can be leveled up by upgrading weapons and summons.
When an upgrade skill's level exceeds a certain threshold, it grants bonus EXP to weapons, summons, and characters of the same element when they're upgraded. In addition, the grand success rate will be boosted. The required upgrade skill level to receive these bonuses varies between each weapon, summon, and character.
An upgrade skill's level can be raised by gaining EXP through upgrading weapons and summons. EXP for upgrade skills' levels can't be gained when power-up items are used to upgrade them.
Power-Ups
Power-up Items grant a set amount of EXP when used to upgrade weapons, summons, and characters, usually enough to gain a few levels.
- Grand Successes don't occur when upgrading with Power-up Items, nor do they grant bonus EXP from Upgrade Skills and Crew Skills.
- Weapon Skills and Upgrade Skills don't receive EXP, either.
Inheritance
Weapons with AX skills can be selected as a base weapon to inherit weapon level, skill level, and uncap status from a selected source weapon. The source weapon needs to have the same name as the base weapon.
- The base weapon will only inherit stats that are higher than its own.
- The base weapon will not inherit the source weapon's AX skill.
Select a base weapon on the Weapon Upgrade screen to perform inheritance.
Plus Marks
- Main article: Plus Mark
Characters, weapons, and summons can be upgraded using 
Weapon Plus Mark or 
Summon Plus Mark, which can be obtained by several methods.