Armored Core VI: Fires of Rubicon: Walkthrough & Boss Guide

You play as the mercenary C4-621 (Raven), dropped onto Rubicon 3. Chapter 1 opens with “Illegal Entry” (first boss: AH12: HC Helicopter) and runs through eleven missions in the order Fextralife lists them: Illegal Entry, Destroy Artillery Installations, Grid 135 Cleanup, Destroy the Transport Helicopters, Destroy the Tester AC, Attack the Dam Complex, Destroy the Weaponized Mining Ship, Operation Wallclimber, Retrieve Combat Logs, Investigate BAWS Arsenal No. 2 and Attack the Watchpoint. The chapter ends with “Attack the Watchpoint”, where you first defeat ENTANGLE / Sulla and then AAP07: Balteus. Balteus is protected by Pulse Armor that negates damage until it is depleted; breaking it staggers him, which is your window for heavy damage.

Chapter 2 has three missions: Infiltrate Grid 086, Eliminate the Doser Faction and Ocean Crossing. The chapter's bosses are EC-0804 Smart Cleaner and the C-Weapon IA-13: Sea Spider. Impact-heavy weapons that build stagger are the usual answer to both.

Chapter 3 is the longest chapter (thirteen missions) and contains the first Decision Missions, which lock you out of alternatives for that playthrough: Eliminate V.VII (hidden), Tunnel Sabotage, Eliminate the Enforcement Squad and Destroy the Special Forces Craft. It ends with “Destroy the Ice Worm” and the boss IA-02: Ice Worm. Other bosses here include “Honest” Brute (MILK TOOTH) in “Eliminate ‘Honest’ Brute”.

Chapter 4 runs Underground Exploration (Depth 1–3), the Decision Missions Intercept the Redguns and Ambush the Vespers, Unknown Territory Survey and finally “Reach the Coral Convergence”. Its boss list includes G5 Iguazu (HEAD BRINGER), G1 Michigan (LIGER TAIL), V.V Hawkins, V.VIII Pater, V.IV Rusty (STEEL HAZE), V.VI Maeterlinck, G3 Wu Huahai and the chapter-ending Ibis, IB-01: CEL 240.

Chapter 5 begins with “Escape” and “Take the Uninhabited Floating City”, then splits on a Decision Mission. The Fextralife Endings Guide ties “Intercept the Corporate Forces” to the “Fires of Raven” ending and “Eliminate ‘Cinder’ Carla” to the “Liberator of Rubicon” ending; both are available on New Game and New Game+. Per Wikipedia, siding with Carla ends with a fight against Ayre (IB-07: SOL 644), who turns on C4-621 to protect the Coral, while Rusty dies defending Rubicon. Siding with Ayre means disabling the Xylem with Rusty and the RLF, killing Carla, and then fighting Handler Walter (IB-C03: HAL 826). In the Carla mission you also face FULL COURSE (“Cinder” Carla) and the AI-controlled CIRCUS (“Chatty” Stick); V.II Snail (OPEN FAITH) is an optional boss in the same mission whom you can boost past.

Seeing all three endings takes three playthroughs. Fires of Raven and Liberator of Rubicon are both reachable on New Game and New Game+. The third ending, “Alea Iacta Est” (Coral Release), needs the New Game++ cycle, i.e. your third playthrough or later: you must follow a specific route of missions in Chapters 1, 3 and 4. The Fextralife Endings Guide lists the Decision Missions Escort the Weaponized Mining Ship (Chapter 1) and Prevent the Corporate Salvage of New Tech, Eliminate the Enforcement Squad and Coral Export Denial (Chapter 3), plus Chapter 4 steps (Eliminate V.III, Underground Exploration and the Arena), which unlocks MIA, Regain Control of the Xylem and Coral Release. According to Wikipedia, in that ending C4-621 and Ayre defeat Iguazu (ALLMIND's chosen host) and ALLMIND and trigger the Coral Release. Parts and upgrades carry over into New Game Plus, which adds alternate and extra missions.