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How to Unlock Ruinous Oath Rod in Fisch Roblox (October 2025)
By: Dinesh Chauhan
Updated On: September 23, 2025
The Ruinous Oath is the ultimate Stage 10 fishing rod in Fisch Roblox, offering unmatched stats with 95% lure speed, 500% luck, and infinite max KG capacity. This legendary rod requires completing the Crimson Cavern bestiary and collecting 8 crystals, making it one of the most challenging but rewarding items to obtain in the game. This comprehensive guide will walk you through every step of unlocking this powerful rod, from keystones to crystal collection.
Quick Reference: Ruinous Oath Requirements
Requirement
Details
Cost
30,000,000 C$
Location
Crimson Cavern
Main Requirement
Complete Shiny Sparkling Crimson Cavern Bestiary
Additional Tasks
Collect 8 crystals, Complete "A Mutated Dragon" quest
Prerequisites
Access to Luminescent Cavern, Super Flippers, Water Bubble, Light sources
Ruinous Oath Rod Stats & Abilities (October 2025)
The Ruinous Oath stands as the pinnacle of fishing rods in Fisch, offering stats that dwarf all other rods:
Contents
Lure Speed: 95%
Luck: 500%
Control: 0.08
Resilience: 25%
Max KG: Infinite
Stage: 10
Special Passive Abilities
What truly sets the Ruinous Oath apart are its unique passive abilities:
5% chance for slashes that fills up 2% progress every 0.25 seconds
Slash chances increase by 8% every second
25% chance for Luminescent (9x) multiplier
Perfect Catch mechanics: Control bar gradually decreases while progress speed increases by 5% every second
Chance to instantly fill almost the entire progress bar
100% chance for Mastered (16x) on perfect catches
These abilities make the Ruinous Oath exceptionally powerful for catching rare fish and completing bestiary entries efficiently.
Step 1: Preparation Before Starting
Before attempting to unlock the Ruinous Oath, ensure you have these essential items:
Essential Equipment
Super Flippers - For faster swimming through underwater areas
Water Bubble - Extends underwater time significantly
Light Sources - Fairy lantern or ultra bright lantern for dark caverns
Performance Mode - Enable higher brightness and saturation for better visibility
Recommended Items
Shark Head bait - For catching Colossal Blue Dragon
High-tier rods - No-Life Rod recommended for difficult catches
Plenty of C$ - You'll need 30 million for the final purchase
Friends/Team - Some challenges are easier with cooperation
Step 2: Unlocking Luminescent Cavern
The journey to Ruinous Oath begins with accessing Luminescent Cavern, which requires collecting three specific keystones from nine possible locations.
Understanding the Keystone System
Each player receives a unique combination of three keystones needed to unlock Luminescent Cavern. Visit the pedestals near the Red Buoy at Desolate Deep to discover which three you need.
All Keystone Locations & Coordinates
Keystone Name
Location
Coordinates
Specific Instructions
Cliff Keystone
Castaway Cliffs
473, 230, -2159
Small gap beside ledge to second level
Mushroom Keystone
Mushgrove Islands
2666, 130, -717
On top of boat near Alligator area
Fossil Keystone
Ancient Isles
6065, 225.5, 259.5
On wood heap lifted by cranes near merchant
Snowflake Keystone
Snowburrow
2788, 153.5, 2603
Inside cave beside pine tree
Volcano Keystone
Roslit Volcano
-1970, 175.4, 268
Middle stone inside volcano
Skull Keystone
Forsaken Shores
-2797.5, 209, 1544.2
Beside pirate NPC (map fixing area)
Lightning Keystone
Grand Reef
-3406, 134.2, 262.2
Small island left of Shipwright island
Turtle Keystone
Terrapin Island
57, 149.5, 2032
Inside Terrapin Hideaway
Sun Keystone
Sunstone Island
-935, 223, -984
Inside Merlin's Hut
Entering Luminescent Cavern
Once you have your three keystones:
Start at Red Buoy - Dive underwater with proper gear
Navigate to warning sign - Head straight from the buoy
Find glowing blue coral - Take right turn here
Locate Diver NPC - Another right turn leads to the pedestals
Place keystones - Press 'E' to place each keystone on its pedestal
Enter the crack - The wall opens to reveal Luminescent Cavern
Cross Mysterious River - Final barrier before accessing the area
Step 3: Completing the "A Mutated Dragon" Quest
To access Crimson Cavern, you must complete the "A Mutated Dragon" quest by catching a Crimson Mutated Colossal Blue Dragon.
Finding Colossal Blue Dragon Hunts
Location: Left side of Luminescent Cavern during active hunts
Rarity: Exotic
Preferred Bait: Shark Head
Best Conditions: Clear weather, Spring/Summer seasons
Weight: Average 200,000kg (base)
Catching Strategy
Wait for hunt activation - These are timed events
Use Shark Head bait - Increases catch rate significantly
Prepare for challenge - Applies -90% Progress Speed when hooked
Watch for visual cues - Shimmering sound and pop-up appear when hooked
Team up if possible - Makes the difficult catch more manageable
Understanding Mutations
The Colossal Blue Dragon has multiple possible mutations, but you specifically need the Crimson mutation to unlock Crimson Cavern:
Chaotic - Random mutation
Mastered - Enhanced version
Crimson - REQUIRED for Crimson Cavern access
Blessed - Lucky mutation
Silver - Rare metallic variant
Big - Size enhancement
Lunar - Moon-related mutation
Hexed - Cursed variant
Negative - Dark mutation
Electric - Lightning-based
Glossy - Shiny appearance
Albino - White variant
Mosaic - Pattern-based
Luminescent - Glowing effect
Scorched - Fire-related
Translucent - Semi-transparent
Serene - Peaceful variant
Frozen - Ice-based
Spirit - Ethereal version
Shiny - Enhanced appearance
Step 4: Accessing Crimson Cavern
Once you have the Crimson Mutated Colossal Blue Dragon:
Return to quest NPC - Located in Luminescent Cavern
Deliver the dragon - Completes the "A Mutated Dragon" quest
Crimson Cavern unlocks - The gate opens to the new area
Enter Crimson Cavern - A crimson jungle with glowing fungi and red waterfalls
Crimson Cavern Features
Environment: Lush crimson jungle with giant glowing fungi
Notable Landmarks: Giant tree with Crimson King's throne
NPCs: Crimson King, Wixie, Tilli
Special Features: Crab Cage available, no Bait Crate
Step 5: Completing Crimson Cavern Bestiary
The most time-consuming requirement for the Ruinous Oath is completing the full Shiny Sparkling Bestiary in Crimson Cavern.
Crimson Cavern Fish Species
Fish Name
Rarity
Special Notes
Red Spotted Blenny
Uncommon
Day time preferred
Sea Raven
Rare
Clear weather best
Red Crabsquid
Unusual
Night fishing effective
Viperfish
Rare
Pro tip: Use No-Life rod with no bait at night
Red Fangtooth
Legendary
Requires high-tier equipment
Japanese Dragon Eel
Mythical
Very rare, patience needed
Vampire Squid
Exotic
Hunt events only
Lithodes Megacantha
Relic
Extremely rare mutation
Colossal Ancient Dragon
Apex
Boss-level difficulty
Bestiary Completion Strategy
Start with common fish - Build momentum with easier catches
Use appropriate bait - Each fish has preferred bait types
Fish at optimal times - Weather and season affect spawn rates
Focus on one species at a time - More efficient than random fishing
Use Ruinous Oath passive abilities - Once obtained, helps with remaining catches
Join fishing communities - Learn from others' experiences
Understanding Shiny Sparkling Requirements
Shiny chance: 3% (nerfed from 5% in update 1.50.0)
Sparkling chance: Separate from shiny, both required
Strategy: Fish in large quantities to maximize chances
Patience needed: This is the most time-consuming part of the process
Step 6: Collecting the 8 Crystals
After completing the bestiary, you'll need to collect 8 crystals scattered throughout Crimson Cavern.
Crystal Collection Quest
This quest is given by an NPC in Crimson Cavern (likely Wixie based on community references):
Talk to the crystal NPC - Receive the crystal collection quest
Explore thoroughly - Crystals are hidden in various locations
Use bright lantern - Essential for spotting crystals in dark areas
Systematic search - Check all corners, caves, and high places
Work with friends - Makes collection faster and more enjoyable
Pro Tips for Crystal Hunting
Brightness settings: Maximize visibility
Team coordination: Split up to cover more area
Reference guides: Community maps may help (though locations may vary)
Persistence: Some crystals are well-hidden
Step 7: Purchasing the Ruinous Oath
After completing all requirements:
Verify completion - Ensure bestiary is 100% Shiny Sparkling
Collect all 8 crystals - Turn in the crystal quest
Visit the Crimson Cavern vendor - Located near the giant tree
Purchase Ruinous Oath - Cost: 30,000,000 C$
Equip and enjoy - You now have the best rod in the game!
Advanced Strategies & Pro Tips In 2025
Maximizing Efficiency
Use the Ruinous Oath strategically - Its passive abilities make it ideal for:
Catching rare fish for other bestiaries
Farming high-value fish
Completing challenging hunts
Helping friends with their catches
Enchantment recommendations - Based on community testing:
Luck-enhancing enchantments
Lure speed improvements
Control bar adjustments
Bait optimization - Pair with highest-tier bait for maximum effectiveness
Common Mistakes to Avoid
Skipping preparation - Don't enter caverns without proper gear
Ignoring keystone order - Place keystones in the correct pedestals
Underestimating bestiary time - This takes significantly longer than other steps
Poor mutation management - Focus specifically on Crimson mutation
Insufficient funds - Ensure you have 30 million C$ before final step
Frequently Asked Questions
How long does it take to get the Ruinous Oath?
The process typically takes 20-40 hours, with the majority of time spent completing the Crimson Cavern bestiary. The crystal collection and other quests are relatively quick in comparison.
What's the best rod to use before getting Ruinous Oath?
The No-Life Rod is highly recommended for difficult catches like the Viperfish and Colossal Blue Dragon due to its high control and resilience stats.
Can I complete the Crimson Cavern bestiary without Ruinous Oath?
Yes, but it's significantly more difficult and time-consuming. Many players complete the bestiary first, then purchase Ruinous Oath to help with other areas of the game.
Are the crystal locations the same for everyone?
Crystal locations appear to be consistent, but some randomness may be involved. Working with systematic search methods is most effective.
What happens if I lose my Crimson Mutated Colossal Blue Dragon?
You'll need to participate in another Colossal Blue Dragon hunt and try again for the Crimson mutation. The mutation is random, so persistence is key.
Is the Ruinous Oath worth the effort?
Absolutely. With 500% luck, infinite max KG, and unique passive abilities, the Ruinous Oath dramatically improves your fishing efficiency and is considered the best rod in the game.
Can I help friends get their Ruinous Oath?
Yes, many of the challenges (especially crystal collection and dragon hunts) are easier with friends. However, each player must complete their own bestiary and purchase their own rod.
What's the difference between Shiny and Sparkling?
These are separate rarity modifiers for fish. Both must be obtained for each species to complete the Shiny Sparkling bestiary requirement.
Conclusion
The Ruinous Oath represents the pinnacle of achievement in Fisch Roblox, offering unparalleled power and utility for dedicated players. While the journey is long and challenging, the reward of wielding this Stage 10 rod with its incredible stats and unique abilities makes every effort worthwhile.
From navigating the keystone system to mastering the art of catching rare mutations, each step of this guide has prepared you for the ultimate fishing rod acquisition. Remember to prepare properly, work systematically, and don't hesitate to join the community for support and additional strategies.
As you embark on this epic fishing adventure, keep in mind that patience and persistence are your greatest allies. The Ruinous Oath isn't just a rod—it's a testament to your dedication and skill as a master angler in the world of Fisch.
Ready to begin your journey to the Ruinous Oath? Bookmark this guide, gather your equipment, and dive into the mysterious caverns of Fisch. The ultimate fishing rod awaits those brave enough to claim it!
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