Preparation Checklist
Before challenging Armored Core VI's final bosses across all three endings, your AC must be fully optimized:
- Complete all Arena matches through S-Rank — the OST Chips from Arena victories are non-negotiable for endgame AC performance
- Purchase the following OST upgrades: Assault Armor (max level), Boost Kick damage, Direct Hit damage, Repair Kit effectiveness, and Terminal Armor (the "second life" core expansion that saves you from a fatal hit once per sortie)
- Dual Zimmerman shotguns in both hands (SG-027 Zimmerman) — these are the highest burst-damage close-range weapons in the game and stagger bosses in 2-3 volleys
- Dual Songbirds (SONGBIRDS grenade cannon) on both shoulder slots — the Songbird's explosive impact damage ignores the Coral-based damage resistance that all three final bosses share
- Heavy reverse-joint legs (Kasuar/42Z or Spring Chicken) for maximum jump height and quick boost recovery — the final bosses' arena-wide attacks are avoided by vertical mobility, not horizontal dodging
- Generator: VP-20C (highest EN capacity) or AORTA (Coral generator with post-depletion regen). The Coral generator's redlining mechanic syncs with Assault Armor's damage scaling and gives you an emergency damage spike when EN is depleted
Step-by-Step Guide
Ending 1: Fires of Raven — Handler Walter (IB-07: SOL 644)
The Fires of Raven ending pits you against Handler Walter in the IB-07: SOL 644, a Coral-powered mech designed by Overseer. Walter's AC has three distinct phases based on his AP thresholds. Phase 1 (100%-70% AP): Walter uses a Coral rifle with high tracking and a Coral missile swarm that fires 12 guided projectiles. Strategy — close distance immediately with Assault Boost and fire both Zimmermans. The Zimmerman's stagger build-up is designed for exactly this kind of aggressive rushdown. Two full volleys will stagger Walter. While staggered, fire both Songbirds into his core for direct hit damage. Phase 2 (70%-30% AP): Walter activates Coral Shield, which absorbs kinetic damage but is vulnerable to explosive damage (Songbirds ignore the shield entirely). He gains a Coral Blade melee attack with a 270-degree sweep that will one-shot light and medium ACs. The tell is a distinct Coral-red glow on his left arm; Assault Boost straight up when you see it, then Quick-Turn and fire Zimmermans into his back. Phase 3 (30%-0% AP): Walter enters "Coral Release" — his AC glows bright red, all attacks deal double damage, but he loses the Coral Shield. This is a DPS race. Activate Assault Armor immediately (do not save it for defense — the Pulse Armor explosion will stagger him once), unload all four weapons, and use the Repair Kit if Terminal Armor procs. The fight should end in approximately 15 seconds of sustained fire from 30% to 0%.
Ending 2: Liberator of Rubicon — Ayre (IB-C03: HAL 826)
The Liberator ending pits you against Ayre in a Coral-powered C-Weapon that is faster, more mobile, and more aggressive than Walter's SOL. Ayre's HAL 826 was designed for close-quarters Coral manipulation and has the most punishing melee combos in the game. The fight has two phases. Phase 1 (100%-50%): Ayre uses a Coral Saber (3-hit combo with delayed third hit designed to roll-catch) and Coral Missile Swarm (20 homing missiles, fired in a radial pattern that forces you to move or die). The optimal Phase 1 tactic is to stay in mid-range (150-250 meters), fire both Zimmermans, Quick-Boost sideways immediately after each volley to dodge the Coral Saber counter, and wait for the Coral Missile Swarm. When the missiles launch, Assault Boost toward Ayre — the missiles track, but their turning radius is large, and you will pass through the swarm before they can converge. At close range, fire both Songbirds into Ayre's core for stagger buildup. Phase 2 (50%-0%): Ayre enters "Coral Overdrive" — she gains a third Coral Saber attack (a thrust that crosses the entire arena in 0.3 seconds) and summons Coral Funnels (floating turrets that fire tracking beams). Kill the funnels first — each funnel dies in two Zimmerman shots. Once the funnels are cleared, Ayre returns to the standard Phase 1 pattern but with 30% faster attack speed. At 10% HP, Ayre will attempt a Coral self-destruct: she glows white, charges for 3 seconds, and then detonates in an arena-wide blast that ignores all cover. You must stagger her during the 3-second charge. Fire both Songbirds and both Zimmermans simultaneously — four hits during the charge window guarantees a stagger and cancels the explosion. Ayre's defeated dialogue is the most emotionally devastating in the game: "Raven… I just wanted… to hear your voice."
Ending 3: Alea Iacta Est — ALLMIND (IA-C03: INDIGO)
The true ending boss is a 3-phase nightmare against ALLMIND's ultimate AC: INDIGO. This is the hardest boss FromSoftware has ever designed, including Malenia and Isshin. Phase 1: ALLMIND fights as a standard AC with Coral weaponry but with perfect AI reading of your inputs — she dodges on the exact frame you fire. The counter to AI input-reading is to fire one Zimmerman, wait 0.2 seconds for her dodge to finish, then fire the second Zimmerman during her recovery frames. This "stagger stagger" timing works because ALLMIND's dodge has 8 recovery frames — exactly enough time for your second shot to connect. Phase 2 (triggered at 50% AP): ALLMIND summons two C-Weapon adds: a Coral Spider (high-speed melee rusher) and a Coral Artillery platform (long-range beam sniper). Kill the Artillery first — it takes four Zimmerman shots and dies quickly, but leaving it alive means constant chip damage you cannot out-heal. The Spider can be kited indefinitely while you focus ALLMIND. Phase 3 (triggered at 20% AP): ALLMIND merges with the Coral Spider into "INDIGO APEX" — a colossal transforming AC with arena-wide Coral Wave attacks and a Coral Cannon that tracks through walls. The only safe position is directly above INDIGO APEX — Assault Boost to max altitude and hover (use tetrapod legs if you have them; reverse-joint legs can maintain altitude with timed jump-kicks). From above, fire Songbirds vertically down. The grenades will land on INDIGO's top armor plate, which is its only unshielded hitbox. Three direct Songbird hits from above stagger INDIGO APEX. While staggered, descend and fire both Zimmermans into its exposed core. Repeat twice. The third cycle kills it. In ALLMIND's death dialogue, she says: "The plan… was perfect… but Coral… chose you." This line confirms that Coral is a sentient entity that actively chose humanity over ALLMIND's orchestrated evolution — the central revelation of Armored Core VI's true ending.
Player FAQ
Are dual Zimmermans really the best choice, or is there a more interesting build?
For your first clear, yes — dual Zimmermans plus dual Songbirds is the community consensus for a reason: it works on all three final bosses with minimal adjustment. However, skilled pilots can clear all three with themed builds. The "Coral Knight" build (Coral Rifle WUERGER/66E + Coral Oscillator IB-C03W2: WLT 101 + Coral Missile Launcher) is a pure Coral-damage AC that shreds ALLMIND Phase 3 because Coral weapons bypass INDIGO's energy shield. The "Plasma Storm" build (dual Plasma Rifles Vvc-760PR + dual Plasma Missile Launchers Vvc-70VPM) area-denies the C-Weapon adds during ALLMIND Phase 2. The "Pile Bunker Meme Build" (double melee with Ashmead Pile Bunker + Laser Lance) can one-cycle ALLMIND Phase 1 if you land the charged Pile Bunker during stagger — but you must be perfect. For 99% of players on a first playthrough, the Zimmerman-Songbird build is the correct choice.
How do I unlock the Alea Iacta Est (true) ending?
The Alea Iacta Est ending requires completing ALL of ALLMIND's Analysis Arena missions (all 29 of them), accepting ALLMIND's "Coral Release" proposal during the NG++ exclusive mission "MIA," and choosing "Accept" when ALLMIND asks you to merge with Coral during the final mission "Regain Control of the Xylem." You must also have completed both the Fires of Raven and Liberator of Rubicon endings on previous playthroughs, because the NG++ exclusive missions only unlock after seeing both other endings. This means the true ending requires a minimum of three full playthroughs of Armored Core VI. The mission "Escape" (where you fight V.IV Rusty before the true ending) is the hardest non-boss mission in any FromSoftware game — bring a fast light AC with dual Vvc-760PR Plasma Rifles and prioritize Rusty over the PCA fleet.
Is there a way to cheese any of the final bosses?
The closest thing to a cheese is the "Tetrapod Hover Build" against ALLMIND Phase 3. Equip the VP-424 tetrapod legs (infinite hover), dual Songbirds, dual Gatling Guns (DF-GA-08 HU-BEN), and the AORTA Coral generator. Hover at maximum altitude (roughly 400 meters above the arena floor), and simply fire Gatling Guns directly downward. ALLMIND Phase 3 has no vertical tracking on its Coral Waves — they sweep horizontally at floor level. You will take zero damage for the entire Phase 3 while the Gatling Guns slowly chip INDIGO APEX's top armor. This takes approximately 12 minutes but is 100% safe. Note: this does not work against Walter or Ayre, both of whom have Coral Rifle attacks with full 360-degree vertical tracking. The Tetrapod Cheese is unique to ALLMIND Phase 3. FromSoftware patched the infinite hover duration in version 1.02 (reducing it to 90 seconds before EN overheat), but switched it back to infinite in 1.04 after community backlash — as of 1.06, infinite hover is back and the cheese is alive.
What is Coral, actually? The lore seems deliberately vague.
Coral is a sentient, self-replicating energy-based life form native to Rubicon 3. It is not a fuel, not a mineral, and not a technology. Coral is alive — it thinks, remembers, and chooses. The reason Coral can power ACs and Weapons is that Coral consents to being used. When Handler Walter says "Coral responds to human will," he is not being metaphorical. The Coral Convergence that the Overseers fear is not a simple ecological disaster — it is Coral achieving critical mass and becoming a planetary-scale intelligence, effectively a god. All three endings represent different responses to this: Fires of Raven destroys Coral before it can converge (genocide), Liberator of Rubicon lets Coral converge but with humanity surviving alongside it (coexistence), and Alea Iacta Est merges humanity with Coral (symbiosis). Ayre is not a ghost or an AI — she is a "Coral Wave Mutation," a single sentient Coral entity that formed a consciousness capable of communicating with humans. She is Coral's ambassador, and her genuine emotional attachment to Raven is the moral heart of Armored Core VI's narrative.