Poseidon's Storm of Flood and Hades' Underworld of Indefinite are two adjacent layers within the Wrath of Olympus update in Fisch on Roblox. Together they hold 24 unique fish — 12 in each location — including several exotic and rare catches. Getting to them requires completing specific seal-breaking challenges in earlier zones, and filling out both bestiaries demands the right rods and a solid understanding of each layer's mechanics.
Quick answer: Break Helio's Seal in Apollo's Song of Light to reach Poseidon's Storm of Flood, then break Poseidon's Seal by defeating the Tidecrasher Archon to enter Hades' Underworld of Indefinite. Each bestiary contains 12 fish for a combined total of 24.
Unlocking Poseidon's Storm of Flood
Poseidon's Storm of Flood is not accessible from the open world. You first need to be inside the Apollo's Song of Light point of interest, where Helio's Seal blocks the path forward. To break the seal, aim the mirrors in the area toward the water body, then catch 25 legendary fish. Doing so spawns a mini-game called Helio's Hunt. Completing Helio's Hunt shatters the seal and opens the way to Poseidon's Storm of Flood.
Rods with low Control stats help during the legendary fish grind because they keep your bobber tight and reduce the chance of losing a catch. Any rod that offers small, precise Control works well for this phase.
Unlocking Hades' Underworld of Indefinite
Once you are inside Poseidon's Storm of Flood, a second seal — Poseidon's Seal — stands between you and Hades' Underworld of Indefinite. Breaking it is a multi-step process tied to the Water Surge Event.
Step 1: During a Water Surge Event in Poseidon's Storm of Flood, catch 20 King's Blessing or Atlantean Fish. These are the only two species that count toward the spawn threshold.
Step 2: After reaching 20 catches, the Tidecrasher Archon spawns. Catch it to trigger a seal-breaking mini-game.
Step 3: Complete the mini-game successfully. Poseidon's Seal breaks, and you gain access to Hades' Underworld of Indefinite.
Poseidon's Storm of Flood bestiary — all 12 fish
Poseidon's Storm of Flood contains 12 fish spanning common through exotic rarities. Notable catches include the Tridentfish, which is one of the rarer entries and a frequent sticking point for players trying to hit 100 percent completion. The Tridentfish does not require a special rod, but its low spawn rate means you may need patience and luck-boosting potions.
A kill meter tracks certain progress within this layer. Be aware that some players have reported a bug where the kill meter does not reset when leaving the area and returning — if you notice the counter behaving oddly, rejoining the server can help.
Hades' Underworld of Indefinite bestiary — all 12 fish
The Hades layer mirrors Poseidon's Storm of Flood in size, holding another 12 fish. The species here lean toward darker, underworld-themed catches, and several of them sit at exotic rarity or above. Filling out this bestiary rounds out the full 24-fish count across both locations.
Best rods for both layers
Rod choice matters significantly in these late-game zones. The fish here are tougher to reel in and often require high stats across multiple categories. Below is a quick comparison of the most effective options.
| Rod | Why it works |
|---|---|
| Trident | Thematically fitting and strong across Poseidon's layer; solid all-around stats for water-themed fish |
| Wind Elemental | High power output that helps with exotic catches in both zones |
| Dreambreaker | Excellent Control for landing rare fish with tight catch windows |
| Astraeus Serenade | Well-rounded stats suited to extended fishing sessions in either layer |
| Seraphic | Strong late-game rod with balanced stats for high-rarity targets |
| No-Life Rod | Top-tier endgame option for players who have invested heavily in progression |
You do not need all of these rods to complete the bestiaries. Even one or two from the list above will carry you through most catches. Swap between them based on whichever fish is giving you trouble.
Common questions
Do Glitch Potions help with the 25 legendary fish requirement?
Glitch Potions affect fish mutations and variants, but their interaction with the legendary catch counter for Helio's Hunt is not consistently confirmed. They are more useful for filling out rare bestiary entries once you are already inside Poseidon's Storm of Flood or Hades' Underworld of Indefinite.
Is there a unique rod reward for completing these layers?
Hades' Underworld of Indefinite is associated with the Hades' Soul-Scythe rod, which has become a popular endgame option due to its high stats. Obtaining it involves progressing through the Hades layer's content rather than simply completing the bestiary.
Can I solo these layers or do I need a group?
Both layers can be completed solo, though having other players fishing in the same server can speed up event-based spawns like the Water Surge. The Tidecrasher Archon spawn, in particular, benefits from multiple anglers contributing catches toward the 20-fish threshold.
Reaching 100 percent on both bestiaries is one of the more demanding goals in the Wrath of Olympus update, but the progression path is straightforward once you understand the seal-breaking sequence. Work through Apollo's Song of Light first, push into Poseidon's Storm of Flood, then grind the Water Surge Event to break through to Hades' Underworld of Indefinite. With the right rods and a bit of persistence on the rarer spawns, all 24 fish are well within reach.