Armored Core 6: How to beat the CEL 240 boss in AC6
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Despite being a FromSoftware title, there aren’t too many classic FromSoft bosses in Armored Core 6. While bosses like Balteus and the Sea Spider are challenging, most players should be able to defeat them within a short amount of time. Unfortunately, the streak of “easier” bosses completely grinds to a halt when you reach CEL 240 at the end of Chapter 4.

CEL 240 is an Ibis Series enemy that appears in Institute City when you are on the mission “Reach the Coral Convergence.” This mission completes Chapter 4, but you likely won’t be seeing the start of Chapter 5 for several hours. CEL 240 takes an extremely long time to beat unless you have an impeccable talent for mech fighting or the perfect build from the get-go.

In this guide, I will explain how I was able to beat CEL 240 in AC6 so you might not have to repeat the fight for hours on end.

How to beat CEL 240 in AC6

First and foremost, there are a couple of settings you want to change in AC6 for this fight. First, you want to go into Camera Settings and change your Camera Sensitivity to 10. Trust me, this is a requirement. Next, I recommend turning down your Voice Volume in Audio Settings. While this isn’t required, both Walter and Ayre can get quite annoying throughout this fight and you want to ensure you can hear every audio cue from CEL 240 instead of hearing those character’s voices.

With those settings in place, we can move on to fighting CEL 240.

Learning CEL 240’s attacks

CEL is the fastest boss in AC6 by a country mile. You will likely not be able to keep up with it on your screen, as she moves too fast for you to keep her in your line of sight at all times. My number one piece of advice is to simply try to predict where the boss will move and if you can’t find it, then simply start dodging.

When CEL zips away off your screen, it is likely gearing up for one of two attacks: a giant beam of red energy that is fired in a straight line or a multi-beam attack that follows your character. CEL could also fire one of its fan attacks, where two or more fans of energy are shot at you. You will need to learn the attack and dodge patterns for all of these attacks. I found that dodging one way and then immediately the other way was the best strategy for most of the attacks.

Dodging the giant beam from CEL. | Screenshot by Upcomer

If you see CEL gearing up for one of its two energy beam attacks, you want to time your dodges correctly. Listen for the audio cues and dodge right before either of the attacks is set off.

Aside from those main attacks, you want to try and get as close to CEL as you can. Firing at long range will not work due to how fast the boss moves; it will dodge all of your long range attacks with ease. Of course, remaining close to CEL is difficult given how fast it moves and that it doesn’t stay in the same spot for long.

There are some attacks, though, where CEL will remain still for a second or two. You need to strike during these times, as it’s one of your only chances to deal some damage.

Beating CEL 240 in phase two

Of course, all of this advice is mostly for phase one of the fight. That’s right, if you haven’t depleted CEL’s health up to this point, there is an entirely other phase you need to beat. During phase two of the fight, CEL will completely transform its attack patterns. The boss will now attack you with much wider and more devastating moves that are nearly impossible to dodge.

CEL 240 in phase two. | Screenshot via Upcomer


My recommendation for this phase is to worry about dodging more than attacking. You need to ensure you keep your health up and only try to deal damage when there is an opening. There is far less leeway during phase two than there was in phase one.

The best build for CEL 240

I was able to beat CEL 240 using a very specific build that is able to stagger it with a couple of shots and then deal massive damage with a single attack during the staggered period. The exact build calls for dual Ice Worm Stun Needle Launchers on your shoulders, a Pile Bunker on your Left Arm, and a Gatling Gun on your Right Arm. All of this is on top of the mini-tank legs with the Assault Armor expansion.

You can read about my full build for CEL 240 in a previous guide, but here is the basic strategy for the fight using this build:

  • At the start of the fight, dodge the mini-beams that CEL shoots down and then dodge to the left to avoid the fan attack.
  • CEL will stop near you after coming down to the ground from firing those attacks.
  • When it is still on the ground, fire both of your Stun Needle Launchers at it.
Staggering CEL with the Stun Needles as soon as the fight begins. | Screenshot via Upcomer
  • This will stagger CEL if you hit both shots. If you stagger it, get close, charge up your Pile Driver, and then release the attack. You need to ensure you’re close enough for the attack to hit.
  • If it hits, then CEL should lose over half of its health. From this point on, you need to continue to land shots with your Stun Needle Launchers while also firing your Gatling Gun non-stop.
  • When you hit your Stun Needle Launcher shots, try to get close enough to get a charged Pile Driver attack in.
  • This strategy works for both phase one and phase two, but you need to be careful firing your Stun Needle Launchers during phase two, as your mech briefly stops to fire them. Don’t get caught in the middle of an attack from CEL while trying to fire the launchers.
  • I found that after CEL delivers one of its big attacks is a perfect time to fire the Stun Needle Launchers. However, if you stagger CEL while it’s in the air, you will have to fly to it to land a Pile Driver attack.

This fight took me well over three hours to beat, so don’t expect to get past CEL 240 quickly. Using my strategy and build gives you the best chance to beat this boss as quickly as possible, though.

Joey Carr is a full-time writer for multiple esports and gaming websites. He has 7+ years of experience covering esports and traditional sporting events, including DreamHack Atlanta, Call of Duty Championships 2017, and Super Bowl 53.