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Triaggelos Boss Fight Guide

Defeat Triaggelos by learning the attack tells for all three phases and saving burst damage for stun windows. This is for players who want a clear phase-by-phase plan for clearing the fight more consistently.

Beginner 8 min read 17 viewsUpdated 27 days agoby LongBeam
Adapted from How to Beat Triaggellos Boss Fight | Step-By-Step Guide ► Arknights Endfield

Defeat Triaggelos by learning each phase's attack patterns, saving your strongest abilities for stun windows, and handling adds efficiently. You'll recognize when to interrupt, dodge, and burst, making the fight much more manageable. Phase transitions and visibility challenges are key, and the fight rewards careful resource use.

Quick answer

WhatAnswer
Phases2 phases
Best damage windowWhen the boss is stunned
Phase 2 damage ruleAttack after the adds are defeated
Phase 3 visibilityInvisible, sometimes with a purple aura
Phase 1 interruptUse 1, 2, 3, 4 or E to cancel heavy attacks
Patch may have changed this

This guide describes three distinct phases (red, green, purple), but some game versions list only two. Check the in-game UI for current phase structure.

Learn the three phases

Triaggelos cycles through distinct combat phases, each defined by a color and unique mechanics. The boss opens with the red phase, focusing on ranged and heavy attacks that must be interrupted. The green phase introduces arena-wide hazards and a wave of smaller enemies. The final phase, purple, is marked by the boss becoming invisible or partially visible, with new attack patterns built around tracking and positioning.

Triaggelos begins the fight in the red-colored phase one, confirming the start of phase one.
  • Phase 1 (red): Focuses on interrupting heavy attacks and careful dodging.
  • Phase 2 (green): Begins with shockwave arena attacks and requires defeating spawned adds before the boss becomes vulnerable.
  • Phase 3 (purple): The boss turns invisible, sometimes only highlighted by a purple aura. Tracking and hitting is possible even during full invisibility.

You will learn the attack tells and counter strategies for each phase as the fight progresses.

Handle the red phase

The opening phase tests your ability to interrupt and dodge efficiently. Follow these steps to survive:

  1. Easy to dodge by running or using the dodge move. 0:01
  2. Use abilities tied to 1, 2, 3, 4 or your E assist skill for interruption. 0:31
  3. Patience is rewarded in this phase; heavy attacks happen often.
  4. The boss glows red before a heavy slam — run or dodge to avoid.
The boss displays a red circle, signaling a heavy attack during phase 1.

Save burst damage for stuns

Stun windows are the best opportunity to inflict heavy damage. The boss is vulnerable and will lose health rapidly during this period. Focus your ultimates, assist skills, and signature abilities on these moments for maximum effect. This principle applies in every phase: avoid burning key damage abilities outside stun windows unless survival demands it.

Combat is intense and burst abilities are being used, but it is not unambiguously a stun window for maximum damage.
  • When Triaggelos is stunned 1:29, unload your highest-damage skills.
  • Holding back until these windows ensures you can clear phases much faster and reduce overall risk.

Clear the green phase safely

Phase two introduces both arena hazards and adds. Strategy and timing are vital here:

  1. Start phase two by using originium saplings as cover to avoid shockwaves. 1:29
  2. Boss will spawn smaller enemy types; defeat these before the boss becomes vulnerable. 1:59
  3. Move away from the areas marked by incoming spikes.
  4. Later in the phase, rocks cause shockwaves — jump over them to avoid damage.
  5. After clearing enemies, you can use all abilities freely as the boss does not use critical attacks. 2:29
  6. Phase repeats attacks and hazards until the boss is stunned and the fight advances. 2:58
Phase 2 begins with the boss, adds, and protective points visible on the battlefield.

Track the invisible purple phase

The final phase challenges your ability to keep up with attacks while tracking the boss's position. Follow these steps:

  1. The boss may be entirely invisible or highlighted only by a purple aura. 3:28
  2. Damage removes invisibility and makes the boss easier to track.
  3. Missiles are telegraphed by ground markers, so move out of their range quickly.
  4. The direction is fixed once fired. Run to the side or get behind the boss after the attack. 4:20
  5. Unload burst skills once the boss is stunned to finish the fight.
The purple aura signaling phase three and partial invisibility of Triaggelos is visible, illustrating the challenge of tracking the boss during this stage.
The beam is easy to avoid once the line appears.
Tip

Stay close and move behind the boss after its attacks for easier targeting. Watch for ground markers and attack tells to minimize damage taken.

Also worth knowing

Before you commit
  • Use a scan ability in phase three. A scan effect reveals Triaggelos clearly while it is invisible and can interrupt its cloak.
  • Expect poor visibility on mobile. On low graphics settings, the purple aura is difficult to spot, making phase three much harder.
  • Overlevel the fight if the mechanics keep beating you. A strong team at level 60 can steamroll it, even if mechanics are not executed perfectly.
  • Treat the trimmed medal as a separate goal. Earning the trimmed medal for this fight is much more punishing than completing the basic clear.

Frequently asked

How do you stop Triaggelos' heavy attacks?

Use character abilities on the number keys or a character assist with E to interrupt the attack. Dodging also works, but interrupting is better because it stops the move and still lets you deal damage. Save those tools for the heavy attacks because they happen often in the first phase.

When can you damage Triaggelos in phase 2?

You need to clear the smaller enemies first. After that, the boss becomes vulnerable and you can attack freely until the next shock wave sequence starts. This phase also has no critical-hit attacks, so it is a good time to spend your stronger abilities.

Can you hit Triaggelos while it is invisible in phase 3?

Yes, you can still hit it even when it is invisible. A purple aura may appear around it, and damage will also remove the invisibility, making it easier to track. A scan effect from comments can also help reveal it more clearly.

What is the easiest way to beat the boss overall?

Learn the phase-specific tells, dodge the obvious area attacks, and spend your strongest damage when the boss is stunned. The fight is much easier if you do not waste burst abilities before a stun window. Phase 3 is usually the least dangerous once you stay behind the boss after its attacks.

Arknights Endfieldboss fightcombat mechanicsphase guide

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