The Short Answer
Reach level 500, complete 100% of the Luminescent Cavern Bestiary, and bring the currently listed 1,000,000 C$ to the rod pedestal inside the cavern. Money alone will not unlock it; an incomplete Bestiary keeps the purchase blocked.
Check the Three Requirements
- Level 500 or higher.
- Every required Luminescent Cavern Bestiary entry completed.
- At least 1,000,000 C$ at the August 25, 2026 price.
Finish the Bestiary Before the Pedestal
Treat the Bestiary percentage as the real workload. Open the cavern collection view, identify the missing rows, and target them one by one instead of repeatedly visiting the rod. Each missing catch may have its own time, weather, bait, or event requirement.
Buy Luminescent Oath
Once level and Bestiary requirements are both complete, return to Luminescent Cavern and use the rod pedestal. If the prompt does not complete, check the displayed Bestiary percentage and your live price before assuming a bug. A small UI delay is different from an unmet gate.
Know the Skill Check
Luminescent Oath is built around strong perfect-catch execution and valuable mutation outcomes. Its base control and resilience are not especially forgiving, so the purchase price does not automatically make it easier than Heaven's Rod. Use the next-rod comparison if you are still deciding between money, XP, and catch comfort.