Phoenix Jewels are used to upgrade C-grade mercenaries to their hero ranks. They can drop from Expert's Material Box, and they can also be crafted.
Mercenary upgrades[]
The following mercenaries can be upgraded using Phoenix Jewels:
Each mercenary can be upgraded twice using Phoenix Jewels. The first upgrade can be performed at level 80 and requires 20 Phoenix Jewels. The second upgrade can be performed at level 100 and requires 30 Phoenix Jewels.
Crafting[]
| Level | Item | Required Items | Workload | Exp Gain/Batch |
|---|---|---|---|---|
| 24 |  Phoenix Jewel x 2
|
[Phoenix Crystal]×20 [Energy of Atmosphere]×4 [Flame Element Shard]×40 |
400,000 | 8000 |