The toolbox is the only item in the Vestibule that has to be unlocked first before use and can be upgraded by the player without the need to buy a DLC. It will be unlocked after Gauntlet Ⅱ is completed on Normal. As the player progresses through the Raid Mode stages, they will unlock the ability to upgrade the toolbox by using the Black Phone inside the Vestibule.
In most versions of the game, custom parts can only be upgraded if two parts of the same level are owned, for example, Fire Ammo Lv. 1 can only be combined with another Fire Ammo Lv. 1, which will create Fire Ammo Lv. 2, and so on. Exclusive to the Nintendo Switch version of the game is the ability to combine parts regardless of their level with the use of the Part Booster custom part.
Certain levels of parts can only be acquired by combining parts with the toolbox, custom parts at Lv. 5, 6, 7, 8, 12, 13, 14, 15, 16, 17, 18, 19 and 20 cannot be obtained by evaluating albums with the Jukebox.
The toolbox can only be upgraded after certain Gauntlets in Raid Mode have been completed, note that for a Gauntlet to count as being completed, all stages in it must have been finished at least once.
|Rank 1||Gauntlet Ⅱ|
|Free||Episode 1: Penal Colony||???|
|Rank 2||Gauntlet Ⅳ|
|20,000||Episode 2: Contemplation||Combined Parts Max Level: 3 to 5|
|Rank 3||Gauntlet Ⅵ|
|130,000||Episode 3: Judgment||Combined Parts Max Level: 5 to 7|
|Rank 4||Gauntlet Ⅷ|
|400,000||Episode 4: Metamorphosis||Combined Parts Max Level: 7 to 9|
|Rank 5||Raid Mode Ω-01|
|1,000,000||Episode 4: Metamorphosis||Combined Parts Max Level: 9 to 19|