Doom of Mokhaiotl delve boss guide 2026: phases, delve levels, rewards and strategy

What is Doom of Mokhaiotl?

The Doom of Mokhaiotl, also called Osto-Ayak meaning Under-Creature, is a giant insect-like demonic boss released on 23 July 2025 as part of the Varlamore: The Final Dawn update. It sits in the Ruins of Mokhaiotl, deep beneath the Tlati Rainforest in the Varlamore region.

Unlike traditional raids or quest bosses, it is a delve boss with a unique progression system. Every time you defeat it, it burrows deeper into the next delve level. Each deeper level increases its hitpoints and adds or enhances mechanics. You can choose to continue delving — risking accumulated drops — or claim rewards and leave, which resets the delve to level 1.

How to reach the Ruins of Mokhaiotl

The ruins are located beneath the Tlati Rainforest. You can travel there via the Mokhaiotl waystone, the Pendant of Ates to Kastori then running northwest, or the Quetzal whistle to Tal Teklan then running east to the Tonali Cavern.

Inside the Crypt of Tonali, you can search a chest to obtain ancient teleporters. Placing them within 30 tiles of each other creates fast travel back to the ruins, which is essential since each delve cycle requires a return trip.

• Mokhaiotl waystone — direct teleport to the ruins.
• Pendant of Ates → Kastori → run northwest.
• Quetzal whistle → Tal Teklan → run east to Tonali Cavern.
• Ancient teleporters from the Crypt chest speed up return trips.

The delve progression system

The delve system is the defining mechanic. Each time you defeat the Doom, it drops one level deeper. Delve levels run from 1 to 8, then deep delve continues beyond 8 without a hard cap. Each level adds hitpoints and activates new mechanics.

The key decision is when to stop. Claiming rewards resets you to delve 1 and secures all accumulated drops. Dying also resets to delve 1 and forfeits all unclaimed drops. The longer you delve without claiming, the more risk you take — a single death wipes the entire accumulated loot stack.

Mechanics by delve level

Orb attacks are present from delve 1: the boss fires magic (blue) and ranged (green) projectiles from a distance, blocked by praying. Melee attack when directly adjacent. The Rock throw shatters and disables protection prayers, then launches a magic or ranged projectile.

The Shockwave attack activates around 1 minute into the fight and is countered using volatile earth nodes scattered across the arena. The Shielded phase gives the boss 100% resistance to poison and venom and makes it immune to thralls.

At delve 5 and above, the Burrowed phase activates: the boss can dig through the ground, moving unpredictably. It gains 100% freeze resistance, which removes freeze-based control strategies. Demonic larvae spawn and must be killed before they are absorbed by the Doom, or they buff it. Acid blood creates hazardous ground tiles that damage players standing in them.

• Delve 1-4: Orb attacks, Rock throw, Shockwave, Shielded phase.
• Delve 5+: Burrowed phase — burrowing, 100% freeze resistance, unpredictable movement.
• Delve 5+: Demonic larvae spawn — kill before absorption or the boss buffs.
• All delves: Acid blood tiles damage players; Earthen shield mechanic.

Rewards by delve depth

Rewards scale with delve depth. Uniques unlock at specific levels: Mokhaiotl cloth at delve 2, Eye of Ayak at delve 3, Avernic treads at delve 4, and the Dom pet at delve 6 or beyond. Drop rates for all items increase up to delve 9.

Common drops include dragon platelegs, runes, ores, seeds, and demon tears. The quantities of common drops are modified by a multiplier that increases with delve level, so deeper delves yield more of the same items even before uniques become available.

• Delve 2: Mokhaiotl cloth unlocks.
• Delve 3: Eye of Ayak unlocks.
• Delve 4: Avernic treads unlocks.
• Delve 6+: Dom pet unlocks.
• Common drops scale with delve multiplier up to delve 9.

Death penalty and reclamation

Unlike most bosses, dying to the Doom sends you to the lobby area rather than your respawn point. This is similar to Yama, the Master of Pacts, and keeps you close to the fight for a quick retry.

The reclamation fee is reduced by 75% until you have completed 20 total delves. After that, the standard death cost applies. The practical implication: early delves are a low-risk learning phase, and the death penalty only becomes meaningful once you have built up enough kills to lose.

Strategy and optimal gear

Early delves (1-4) are comparable in difficulty to the Corrupted Gauntlet. Focus on prayer switching for orb attacks, using volatile earth nodes for the shockwave, and staying adjacent for melee when safe.

Deep delves (5+) require mechanical skill and composure. The burrow phase means you cannot rely on position prediction. Freeze is ineffective, so burst damage strategies that depend on freeze control must be rethought. Priority is: destroy demonic larvae before absorption, avoid acid blood tiles, and claim rewards before a death erases everything.

Optimal gear follows the standard high-meleee dps setup: best-in-slot melee weapons with high special attack availability, dragonhide or equivalent body for defence, and food. The fight is not gear-gated by level requirements, but the practical gear floor is similar to Corrupted Gauntlet difficulty.