Outerpedia

Deep Sea Guardian Joint Challenge Guide

By Sevih · Updated Jun 16, 2026

Joint Challenge boss. The boss gains for 9 turns after using S3. Remove it with or . Increased damage from StrikerStriker, reduced from AoE attacks. Enemies without buffs take at end of boss turn.

Difficulty

Deep Sea Guardian

Deep Sea Guardian

waterstrikerLv. 120

Immunities

6,000Attack
0Defense
2,000,000Health
274Speed
10%Crit Chance
150%Crit DMG
0%Crit DMG Reduc
0%Penetration
18%DMG Increase
18%DMG Reduction
168Effectiveness
240Resilience
WG60WG

Lv. 120 — Joint Challenge · Defeat Deep Sea Guardian Very Hard

Skills

Humboldt Smash

All Enemies

Attacks all enemies. Inflicts Bleeding on all targets for 3 turns. If there is only 1 target, steal all buffs.

Colossal Splash

CD 3All Enemies

Attacks all enemies. Inflicts 2 Bleeding on all targets for 3 turns. (Ignores Immunity, Irremovable)

Architeuthis Cutter

CD 4All Enemies

Attacks all enemies. Detonates all Bleeding stacks on the target and grants Invulnerability to the caster for 9 turns.

The Peculiarities of Deep Sea Squid

(Passive Effect) When any character with Invulnerability gains a turn, their Ultimate Skill cooldown is reduced by 1 turn, regardless of whether they are an ally or enemy. Reduces all enemies' Effectiveness by 90% and increases the caster's Bleeding Damage Dealt by 100%. At the end of the caster's turn, deals Fixed Damage equal to 10% of the target's Max Health to enemies without any buffs. Increases damage taken from StrikerStriker enemies, and greatly reduces damage taken from attacks that target all enemies. Cursed/Fixed Damage to the Boss cannot exceed 10000. Deals significantly more damage when attacking fewer targets.

Enraged

Single Target

Becomes Enraged every 3 turns. Enraged: Grants an irremovable effect to the caster that increases Attack and reduces damage taken for 3 turns. Restores 10% Weakness Gauge. Enraged lasts for 3 turns. Thalassophobia: Used when Enraged ends. Deals heavy damage to all enemies.

Tips and teams below are written for Very Hard.

Tactical Tips

  • Any character with gains on their Ultimate.
  • At turn end, deals 10% Max HP to enemies without buffs.

Recommended Characters

KanonfirestrikerPoolside Trickster Reginawaterstriker

Kanon, Poolside Trickster Regina

Essential pick for score bonus.

CarenwaterstrikerPoolside Trickster Reginawaterstriker

Caren, Poolside Trickster Regina

boss's .

AerfirestrikerKappaearthdefenderElizadarkrangerReginalightmage

Aer, Kappa, Eliza, Regina

boss's .

DeltaearthstrikerFranearthranger

Delta, Fran

buff (boss is fast).

Monad Evalighthealer

Monad Eva

and support.

Suggested Teams

Monad Eva
light
healer
Monad
Eva
Kanon
fire
striker
Kanon
Poolside Trickster Regina
water
striker
Poolside Trickster
Regina
Tamara
water
ranger
Tamara
Remove from boss ASAP with or . Keep at least one buff on your team to prevent boss's .