Home News Arcane Lineage Bosses: Ultimate Defeat Guide

Arcane Lineage Bosses: Ultimate Defeat Guide

by Ellie May 22,2025

In the thrilling world of Arcane Lineage, bosses present a spectrum of challenges, ranging from easy targets for new players to formidable foes requiring multiple teams to conquer. Each boss brings unique mechanics and demands strategic planning and patience to overcome, offering some of the most coveted loot and items in the game. Dive into our comprehensive Arcane Lineage Boss guide to equip yourself with the knowledge needed to tackle these epic encounters.

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Table of Contents

  • Arcane Lineage Boss List
  • King Slime
    • King Slime Location
    • King Slime Fighting Strategy
    • King Slime Drops and Rewards
  • Yar’thul, the Blazing Dragon
    • Yar’thul Location
    • Yar’thul Fighting Strategy
    • Yar’thul Drops and Rewards
  • Thorian, the Rotten
    • Thorian Location
    • Thorian Fighting Strategy
    • Thorian Drops and Rewards
  • Metrom’s Vessel
    • Metrom’s Vessel Location
    • Metrom’s Vessel Fighting Strategy
    • Metrom’s Vessel Drops and Rewards
  • Arkhaia and Seraphon

Arcane Lineage Boss List

BossLocationDifficulty
King SlimeAround the CityEasy
Yar’thul, the Blazing DragonInside Mount ThulNormal
Thorian, the RottenDeep in the Cess GroundsHard
Metrom’s VesselDeeproot CanopyVery Hard
SeraphonUnlocked by ranking up in the Church of RaphionHard
ArkhaiaUnlocked by ranking up in the Cult of ThanasiusVery Hard

King Slime

While considered more of a mini-boss due to its lesser threat compared to other Bosses in Arcane Lineage, King Slime should not be underestimated, as it can still challenge low-level players. Note that defeating King Slime does not yield soul points.

King Slime Location

King Slime spawns after 100 Slimes are defeated on the server. It appears near the city closest to where the last slime was killed, and a notice on the Quest Board alerts players of the active King Slime quest. The quest involves two steps:

  1. Find the King Slime
  2. Kill the King Slime

This quest has a 30-minute global cooldown on the server.

King Slime Fighting Strategy

With a total of 400 HP (600 HP if Corrupted), King Slime has the lowest HP of any Boss in Arcane Lineage. Its primary attack involves summoning additional Slimes that can overwhelm your party if not managed properly. Additionally, King Slime employs several AOE poison attacks, making it essential to come equipped with potions and cleansing abilities. Once the summoned Slimes are dealt with, defeating King Slime should be straightforward, as its AOE attacks only inflict the Poisoned status without causing direct damage.

AttacksEnergy CostEffect
Slime Creation1Summons a Slime to fight for King Slime.
Crush0King Slime lunges forward, attacking a party member.
Poison Eruption2King Slime throws out a burst of Acid, poisoning your party. This attack cannot be dodged or blocked.
Scalding Spray3King Slime erupts with boiling hot liquid, poisoning your party. This attack cannot be dodged.

King Slime Drops and Rewards

Defeating King Slime can yield the following drops:

  • Random Tier 1 Equipment
  • Slime Buckler
  • Gelat Ring

Completing the King Slime event from the Quest Board offers these rewards:

  • Ferrus Skin Potion
  • Small Health Potion
  • Essence
  • Gold

Yar’thul, the Blazing Dragon

As a fire-type boss, Yar’thul employs Fire and Inferno-based attacks, inflicting Inferno and Burning stacks on your party. He is resistant to fire and physical damage but vulnerable to Hex damage.

Yar’thul Location

To encounter Yar’thul in Arcane Lineage, venture deep into the Desert to find Mount Thul, an active volcano fueled by Yar’thul’s heat. Navigate through the volcano's dark corridors to reach the Blazing Dragon at its heart.

Yar’thul Fighting Strategy

With 1200 HP (1800 HP if Corrupted), Yar’thul compensates for his lower health with high damage output. Most of his attacks inflict Inferno and Burning effects, making this a race against time to defeat him before succumbing to the flames. When his health drops below 50%, he enters a second phase, summoning meteors that can stun and reduce healing. The Dragon Ring and high-quality accessories can ease this battle, and the Corrupted version gains lifesteal.

AttacksEnergy CostEffect
Inferno0Automatically inflicts the Inferno status effect on the player’s party at the start of the battle. This attack cannot be dodged or blocked.
Fire Claw0Yar’thul slashes with fire-imbued claws, dealing light damage.
Magma Pillar2Yar’thul slams the ground, creating a pillar of magma that damages and inflicts 2 stacks of Inferno and 5 stacks of Burn on anyone attacking through it. Lasts 3 turns.
Blaze Core3Yar’thul consumes the parties’ Inferno stacks, healing based on the amount consumed.
Blaze Eruption2Yar’thul slams his arms into the ground, further damaging burning targets and applying scaling Inferno and Burning stacks.
Magma Beam4Yar’thul charges a devastating fire beam for 1 turn, firing it the next for massive damage and affecting adjacent units. This attack cannot be dodged or blocked.
Hellfire1Yar’thul sends an unstoppable wave of fire, lightly damaging the whole party and applying 9 stacks of Burning. This attack cannot be dodged or blocked.
Armageddon6Below 50% Health, Yar’thul may summon a large meteor, dealing massive damage, applying healing reduction, and potentially stunning the party. This attack cannot be dodged or blocked and can be used multiple times.

Yar’thul Drops and Rewards

Upon defeating Yar’thul, you are guaranteed these rewards:

  • Absolute Radiance
  • Permafrost Curse
  • Wild Impulse
  • Heavenly Prayer
  • Breath of Fungyir
  • Narhana’s Sigil
  • Reality Watch
  • Shifting Hourglass
  • Ring of the Dragon
  • The Void Key (Corrupted Yar’thul)

Possible drops include:

  • Dragontooth Blade
  • Dragonbone Gauntlets
  • Dragonbone Spear
  • Dragonflame Shield
  • Memory Fragment
  • Soul Dust
  • Phoenix Tear
  • Resplendant Essence
  • Lineage Shard
  • Skyward Totem

Thorian, the Rotten

Once an animal in the Deeproot Canopy, Thorian became a corrupted, towering abomination with many red eyes and tentacles. Resistant to most elements, he is particularly vulnerable to Holy damage.

Thorian Location

Find Thorian in the deepest part of the Cess Grounds, within the Deeproot Canopy. Head right upon entering and proceed in that direction; his massive size makes him hard to miss.

Thorian Fighting Strategy

Thorian boasts 2,600 HP (3,900 HP if Corrupted), and his battle mechanics are complex. His passive negations heal him if attacked twice in a row with the same attack type, necessitating a variety of attack types. He's resistant to nearly all damage types except Holy, which deals 135% damage, and slightly weak to fire, though only by 10%.

When Thorian falls below 50% Health, he unleashes a devastating attack, inflicting Plague, Curse, and Hexed on the party. This move has a 15-turn cooldown, so it typically won't be used again in the same fight.

AttacksEnergy CostEffect
Cursed Wave2Thorian attacks 3 party members, dealing damage with a chance to inflict Curse.
Overflowing Curse0Starts a minigame; failing results in the Plague status. This attack cannot be dodged or blocked.
Cess Breath1Thorian sends a wave of rotten air, dealing AOE damage and debuffing the party.
Warped Crush1Thorian charges the party, dealing damage to 3 party members.
Blasphemous Obliteration5Upon falling below 50% Health, Thorian devastates the party, applying 1 stack of Plague, 3 stacks of Curse, and 1 stack of Hexed. This attack cannot be dodged or blocked.
Hexed Burst1Thorian sends out a small AOE wave, damaging the party with a chance to apply random debuffs (1 Hexed or 3 Curse).
Plague Rupture2Thorian gives a party member a random debuff, then ruptures them, dealing massive damage scaling with the number of debuffs.

Thorian Drops and Rewards

Defeating Thorian guarantees these rewards:

  • Absolute Radiance
  • Permafrost Curse
  • Wild Impulse
  • Heavenly Prayer
  • Breath of Fungyir
  • Stellian Core
  • Metrom’s Amulet
  • Darksigil
  • Ring of Blight
  • The Void Key (Corrupted Thorian)

Possible drops include:

  • Blightrock Dagger
  • Blightwood Staff
  • Memory Fragment
  • Soul Dust
  • Phoenix Tear
  • Resplendant Essence
  • Lineage Shard
  • Skyward Totem

Metrom’s Vessel

Originally a hero, Metrom’s Vessel now serves as a vessel for Metrom after being possessed and sealed in a Temporal Jail. This jail weakens him significantly.

Metrom’s Vessel Location

Unlike other Bosses, Metrom’s Vessel is a Raid Boss that spawns on a global timer. Accessing this Boss Fight requires a Void Key, obtainable by defeating corrupted versions of other bosses. Once you have a Void Key, await the server-wide notification of Metrom’s Vessel spawning and its location.

Metrom’s Vessel Fighting Strategy

Metrom’s Vessel is a statpile with 10,000 HP (15,000 HP if Corrupted), requiring 30 to 60 minutes to defeat due to his high damage negation. His battle involves two phases with different moves and mechanics.

In the first phase, Metrom’s Vessel has black wings that grant high damage negation. Destroying these wings requires applying status effects and debuffs, but be cautious as fewer wings increase his damage output. Timing your wing-destroying abilities around the transition to the second phase is crucial.

Additionally, Metrom’s Vessel summons Shadeblades, squishy minions with high damage output. Quickly defeating them is essential, as prolonging the first phase increases the chance of him using Oblivion, an undodgeable move dealing 50% max HP to everyone.

In the second phase, Metrom’s Vessel falls, shattering the Temporal Jail. His wings now have Offensive and Defensive modes, granting damage increases or resistance and Thorns Aura, respectively. Destroying these wings remains key, and failing to dodge attacks triggers a Mini Shadebringer attack.

To succeed, coordinate with your team to constantly apply debuffs and damage-reducing effects. Mastery of his timings and wing mechanics makes this battle more manageable.

Phase 1 Attacks

AttacksEnergy CostEffect
Rendering Slash0Metrom’s Vessel lunges at a player, dealing damage and applying 3 Weakness stacks.
Deathbound1Metrom’s Vessel applies 3 stacks of Sundered on 2 random players.
Eclipse1Metrom’s Vessel buffs himself.
Invoke Shadeblades3Metron’s Vessel summons two Shadeblades with 200 HP each. This attack cannot be dodged or blocked.
Hexed Rend3An undodgeable AOE slash that debuffs all players. This attack cannot be dodged or blocked.
Oblivion5Metron’s Vessel uses ancient magic, dealing 50% of everyone’s HP and inflicting Curse. This attack cannot be dodged or blocked.

Phase 2 Attacks

AttacksEnergy CostEffect
Oblivion + Eclipse1Metrom’s Vessel uses Rendering Slash (P1) followed by a Hexed Rend (P1).
Unyielding Fury2An AOE debuff that gives all players 3 stacks of Blind and 2 stacks of Hexed. This attack cannot be dodged or blocked.
Minishade Bringer3Metrom’s Vessel shoots 3 Shadebringers. This attack cannot be dodged or blocked.
Shadebringer1Metrom’s Vessel slashes 3 Shadebringers, hitting the whole party and applying 4 stacks of Cursed. This attack cannot be dodged or blocked.
Blackout2Metrom’s Vessel debuffs the whole party. This attack cannot be dodged or blocked.

Metrom’s Vessel Drops and Rewards

Defeating Metrom’s Vessel guarantees these rewards:

  • Metrom’s Grasp
  • Chaos Orb
  • Expedite Anklet
  • Echo Shard
  • Tempurus Gem
  • Arcanium Crystal

Possible drops include:

  • Darkblood Staff
  • Darkblood Dagger
  • Darkblood Spear
  • Darkblood Hexer
  • Darkblood Sword
  • Darkblood Cestus

Arkhaia and Seraphon

Currently, limited information is available on Arkhaia and Seraphon due to their rarity and complexity. These challenging bosses are not recommended for beginners or new players, even with a strong team. They represent the final bosses in the current development stage.

To unlock Arkhaia, reach rank 20 in the Cult of Thanasius. Arkhaia has 7000 HP and employs a damage-over-time mechanic. Defeating Arkhaia allows you to start a new character with the Inferion race, a powerful and rare starting race in Arcane Lineage.

To unlock Seraphon, reach rank 20 in the Church of Raphion. Seraphon has 4500 HP, and defeating him offers the opportunity to start a new character with the Sheea race, another powerful and rare starting race in Arcane Lineage.

And that concludes our Arcane Lineage Boss guide. For those looking to enhance their gameplay, explore our Complete Arcane Lineage Class tier list and guide.

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