Collaboration Stages · 2 stages
| # | Stage | Boss | Enemies | Rewards | Base HP |
|---|---|---|---|---|---|
| 1 | Iron Will (Easy) |  Boss Enemy No.381 3% |      |  5% | 15,000 |
| 2 | Iron Will (Expert) | Boss Enemy No.381 |    | 25% | 200,000 |