You can boost the status of your gear by setting a Cores in Slots you release on your equipment.

Drills, Slots, and Cores come in 4 colors (red, blue, yellow, and green) and correspond to their same-color counterparts.
Therefore the color of the Core you set should match the color of the Drill you released the slot with.

Slot Colors	Status Up
Red	ATK, MATK
Blue	DEF, MDEF
Yellow	HP, Damage Cap
Green	Elemental ATK, Elemental Resistance

When you open a Slot, you will be able to attach or detach a Core.
You can open a Slot from the "Open Slot" menu by consuming a Drill and Zell.

From the Enhancement Center menu, select "Open Slot" and the gear you want to open the Slot in.

Tap the "Select" button of the Drill you will use. You cannot select a Drill the same color as a Slot that has already been opened.
The success rate of opening Slots will vary depending on the rarity of the Drill you use.
Please be warned that the Drill will be consumed whether you succeed or fail to open the Slot.

On the confirmation screen, check the amount of Zell and the Drill to be consumed and tap the "OK" button.
If the Slot is successfully opened, the color of the Slot will be the same as the color of the Drill you used.

When you set a Core in a Slot, each status will rise depending on the ability of the Core.
You can attach/detach Cores from the "Core Set" menu.

From the Enhancement Center menu, select "Set Core" and the gear you want to set the Core in.
You cannot select gear without Slots.

Tap the "Edit" button on a free gear Slot frame and a list of Cores you can set will be displayed.
Tap "Select" to set the Core in the Slot.
Cores that are already set can be removed with the "Delete" button.

When you enchance a Core, the level and status will rise.
Cores can be enhanced from the "Core Enhancement" menu.

Select "Core Enhancement" from the Enhancement Center menu. Then select the Core you want to enhance.
Two Cores of the same level will be consumed to enhance another Core.
The success rate varies depending on the level of the Core you are enhancing.

Check the Core and the amount of Zell to be consumed on the confirmation screen and tap "OK".
When enhancement is successful, you will get a Core 1 level higher.

When enhancement fails, 1 used Core will be returned, and increase the success rate until it succeeds.
*Although you haven’t selected "Run Again," success rate will be transferred to the next enhancement.

【Core Ability(Lv)】
Normal Type：Ability×Lv
Ex①）ATK Up High CoreLv2 Ability＝ATK+300×2（LV2）＝ATK+600
Ex②）ATK Up High CoreLv3 Ability＝ATK+300×3（LV3）＝ATK+900

Core	Ability	Type
ATK Up High Core	ATK+300	Normal Type
MATK Up High Core	MATK+300	Normal Type
DEF Up High Core	DEF+60	Normal Type
MDEF Up High Core	MDEF+60	Normal Type
HP Up High Core	HP+200	Normal Type
DL Up High Core	Damage Limit+1500	Normal Type
Fire Attack High Core	Fire ATK+20	Normal Type
Water Attack High Core	Water ATK+20	Normal Type
Earth Attack High Core	Earth ATK+20	Normal Type
Wind Attack High Core	Wind ATK+20	Normal Type
Fire Def High Core	Fire DEF+20	Normal Type
Water Def High Core	Water DEF+20	Normal Type
Earth Def High Core	Earth DEF+20	Normal Type
Wind Def High Core	Wind DEF+20	Normal Type
ATK Up Core:R	ATK+100	Normal Type
MATK Up Core:R	MATK+100	Normal Type
DEF Up Core:B	DEF+30	Normal Type
MDEF Up Core:B	MDEF+30	Normal Type
HP Up Core:Y	HP+100	Normal Type
DL Up Core:Y	Damage Limit+500	Normal Type
Fire Attack Core	Fire ATK+10	Normal Type
Water Attack Core	Water ATK+10	Normal Type
Earth Attack Core	Earth ATK+10	Normal Type
Wind Attack Core	Wind ATK+10	Normal Type
Fire Defense Core	Fire DEF+10	Normal Type
Water Defense Core	Water DEF+10	Normal Type
Earth Defense Core	Earth DEF+10	Normal Type
Wind Defense Core	Wind DEF+10	Normal Type

Talk to NPC Sumina at the Enhancement Center and give her your UR earrings or necklace and the "Ultra-Precise Slot Drill" to add and open Core slots.
※Excluding some event accessories.

"You can get the ""Ultra-Precise Slot Drill"" at the Mystery Merchant's exchange in Tower of Time 1F.
※The Core Slot's color will be random."