There are two types of Combiners: Gear Combiner and Consumables Combiner. In Gear Combiner, you can combine the gear that you have to get one new gear of a desired grade.

You can get Normal, Rare, Loyalty, and/or Legendary gear with four to six starts from the Combiner. The result will be random, but if an event is going on you can choose a specific piece of gear from a set that you want.

In the Combine Gear menu, choose the gear rarity and number of stars at the left of the screen to start combining. At the bottom left, you can select the part that you want as the result of the combination. All five parts will be selected by default, but you can select the parts that you want to get as a result, in which case the overall success rate will decrease.

After selecting the grade and parts, you can choose a maximum of 20 items that you can use as combination materials. The success rate will increase as the rarity and grade of the materials are higher. The success rate will be displayed at the bottom left corner. If the combination succeeds, you will get the item that you want. Even if the combination fails, you will get some rewards depending on the total value of the materials.

In the Combine Consumable Items menu, you can either combine gear upgrade materials or gear enhancement materials. You can make Uncommon or Rare Jewels and Rare Materials by combining Gear Upgrade Materials, and can get Silver/Gold/Platinum Enhancement Materials by combining lower Enhancement Materials.

When combining Crystals to make Jewels, you will need 10 Uncommon/Rare Crystals and some gold (5,000 Gold when creating an Uncommon Jewel and 10,000 Gold when creating a Rare Jewel). You can also combine 10 Seal Crests and 5,000 Gold to create an Adventurer Token and 10 Mystical Crests and 10,000 Gold to create a Hero Token in this menu.

To make Rare Materials (third option in the Consumable Item Combiner), you will need Specter Crystals and 10,000 Gold. You can combine 7 Specter Crystals and 10,000 Gold to get a Soul Choice.

Lastly, when combining Gear Enhancement Materials, you will need the same types of Enhancement Materials in a lower grade. A Silver-grade Enhancement Material requires 3 Bronze-grade materials, a Gold-grade material requires 3 Silver-grade materials, and a Platinum-grade material requires 4 Gold-grade materials.

If you combine enhancement materials to make higher enhancement materials, you will get lower overall exp. However, you will spend less gold per exp.