Armored Core 6 Guide: the most difficult bosses and the best build to defeat them

As I explained in my review of Armored Core 6 (here is our review of Armored Core 6), the boss fights featured in the new From Software title are difficult and exhausting but remain, by detachment, the production’s crowning achievement. The Japanese development studio has always accustomed us to epic, pulse-pounding confrontations, and Armored Core 6 is no different.

I decided, therefore, to try to compile my personal ranking of the most complex bosses in Armored Core 6 Fires of Rubicon and provide you with a guide with some tips to defeat them once and for all, pointing out also the build I used for each of them: after this reading, you will no longer be afraid to face CEL 240, Balteus or Ayre.

Before finally proceeding with the list, a clarification: the bosses you are about to read about, are those who I encountered in my first run, having not yet completed the New Game + of Armored Core 6, which is necessary to obtain the true ending of Fires of Rubicon (there are a few additional bosses but the toughest are the ones below). Having made this necessary premise, we can begin.

5) Ice Worm

As in every From Software production, we find a gimmick in Armored Core 6. The Ice Worm was, for me, the easiest boss in the game. This is not to say, however, that the confrontation against the beast is not spectacular. In order to take him down, we must, in fact, use the Stun Needle Launcher, a weapon that shoots electrically charged spikes that allow it to temporarily cancel an impenetrable barrier for any other weapon.

Each time we succeed in hitting the target (the ICE Worm’s “head-mouth”), a mech our ally, a relentless sniper, will fire a shot preceded by a countdown during which the “soldier” will let us know at what point the energy charge of his rifle is: when the worm emerges from underground, the background music will stop and almost in slow motion, we will be able to watch the bullet hit the head of the robotic beast. Collapsed on the ground, the worm will be at our mercy, and only for a few moments will we have a chance to riddle it with lead.

Build utilizzata:

• Right Back Unit: Stun Needle Launcher
• Left Back Unit: Grenade Cannon
• Right Arm: Gatling
• Left Arm: Gatling

4) Sea Spider

The Sea Spider is a surprisingly mangy boss that took me several tries before I saw it capitulate to the mat. The final mission of Chapter 2 confronts us with this mechanical spider, which enters with merit on that special list of enemies that are not particularly complex to deal with but which, in one way or another, end up giving you a lot of trouble. The build as usual is the one with the double heavy machine guns (Gatling) and the grenade cannons on the shoulders instead of the stun needle launchers (have yet to be unlocked).

During the first phase you should always stay underneath the behemoth: by doing so, you will be almost invulnerable to its missiles and you will also be able to dodge its attack with your front legs with ease. In the second phase, you will have to fly as high as possible and shoot him in the “head” to fill his stability bar, with an eye always on the energy of your mech during the aerial phase: if you are about to break the Sea Spider’s balance but the thrusters are almost at the point of exhausting their charge, wait until the charge is restored so that you can hit the boss in the air as soon as you have knocked it out.

Build utilizzata:

• Right Back Unit: Grenade Cannon
• Left Back Unit: Grenade Cannon
• Right Arm: Gatling
• Left Arm: Gatling

3) Balteus

The first major stumbling block of Fires of Rubicon. The two phases that make up the fight vs Balteus are among the most difficult in Armored Core 6 and they tested my nerves: the boss is too strong compared to our knowledge of the game mechanics and our firepower is still quite low. It will take time and several tries before we destroy once and for all this particular flying mech that fires showers of missiles as if we were playing Returnal.

The advice is to go with a full laser and plasma build to temporarily destroy Balteus’ protective barrier as quickly as possible and maximize damage once stunned. For example, I used to mount the laser cannon and plasma missle launcher on my shoulders. Here the Pulse Gun comes in very handy, which will not do who knows what damage but is very useful against energy shields. The last tip before proceeding that also applies to the next boss: stay under him and don’t give him a moment’s rest.

Build used:

• Right Back Unit: Plasma missle launcher
• Left Back Unit: Laser Cannon
• Right Arm: Laser Rifle VE 66LRA
• Left Arm: Pulse gun

2) CEL 240

Here it is, the most feared boss in Armored Core 6, CEL 240, the one who, by all accounts, is the most difficult to defeat, even compared to Malenia of Elden Ring. This mech is extremely fast, splashing from one side of the screen to the other and is, therefore, particularly tiring to follow as it moves. He is also the only boss in the first two runs of Armored Core 6 that need to be destroyed twice. A nightmare? Apparently yes. However, I want to be honest: against CEL 240 I did not have as many problems as I would have expected, so much so that it took me about an hour to succeed in defeating it but, with more care, I could have closed the file even in less time.

The strategy I used to beat him was to equip the Fortaleza crawler, completely or nearly zeroing out my ability to fly. In return, I gained ground mobility that allows me to compete with CEL 240: in this way, his search shots never harmed me, and I was also able to stay on his tail to shoot all the bullets of the heavy machine guns (the defense of CEL 240 is very low) at him from the medium to short range. Once he is stunned, immediately release the electric spikes of your two stun needle launchers (alternatively, grenade launchers are still effective) and repeat in the second phase as well. The key, even in this boss fight, is to always go at the enemy, without letting him breathe.

Build utilizzata:

• Right Back Unit: Grenade Cannon
• Left Back Unit: Stun Needle Launcher
• Right Arm: Gatling
• Left Arm: Gatling
• Legs: Fortaleza crawler

1) Ayre

The top spot in my personal ranking of the most difficult bosses in Armored Core 6 goes to Ayre, the last mech to defeat before the credits roll. Not necessarily everyone will face him in the first run. It will, in fact, depend on the choices you make throughout the campaign. The attacks are very similar to those of CEL 240, and Ayre is also very fast on the battlefield. The set-up then remains the same as in the previous boss fight: Gatling machine guns on both arms, twin stun grenade launchers (or long-range grenade launchers) and tracked Fortaleza to turn our Armored Core into a Ferrari.

Ayre’s moveset is complex to memorize however, there will be a window during the fight in which, after dodging his attack, you will be able to inflict considerable damage: when she approaches you to strike you with her laser blade, dodge backwards so that you find yourself face to face but as her lunge will go awry, you will have a chance to shoot two good spikes in her face that will break 90 to 95 percent of its shield. Outside this window, simply approach and shoot her from medium range, dodging her shots. Follow the same strategy during the second phase of the challenge to finally blow it to smithereens.

Build utilizzata:

• Right Back Unit: Stun Needle Launcher
• Left Back Unit: Stun Needle Launcher
• Right Arm: Gatling
• Left Arm: Gatling
• Legs: Fortaleza crawler