Boss Guides

MIO: Memories in Orbit features 19 powerful boss battles throughout The Vessel: 6 story bosses and 13 optional bosses. These encounters test your combat skills, understanding of the Allocation Matrix system, and mastery of MIO's abilities.

Each boss has unique attack patterns and requires different strategies. Story bosses are required for progression, while optional bosses offer additional challenges and rewards.

Story Bosses (6)

Egis

StoryTrophy: First Kill

First boss encountered in the game. Story-related boss that unlocks early progression.

Location: Early game area

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Don't forget to use modifications that enhance your combat effectiveness

Calderon

Story

Defeating Calderon rewards you with the Old-Fashioned Key.

Location: Various areas of The Vessel

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Don't forget to use modifications that enhance your combat effectiveness

Sol & Vin

Story

A dual boss encounter. After defeating them, climb to the top before the elevator and go right to find Lura's Seal.

Location: Specific area requiring progression

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Don't forget to use modifications that enhance your combat effectiveness

FLORA

Story

Located before the Aviaries Passepartout. After defeating FLORA, go to the right to find this key item.

Location: Area leading to Aviaries

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Don't forget to use modifications that enhance your combat effectiveness

Shii

Story

Final boss of the True Ending path. Must be defeated after completing the Crucible and attaching the severed finger.

Location: True Ending path - The Crucible

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Don't forget to use modifications that enhance your combat effectiveness

Sawlong

StoryTrophy: Aerial Maneuver

A chase boss encountered during a story sequence. You must grapple onto enemies without touching the ground to escape.

Location: Story chase sequence

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Don't forget to use modifications that enhance your combat effectiveness

Optional Bosses (13)

Note: Optional bosses are not required for story completion but offer additional challenges, rewards, and trophies. Some are among the hardest encounters in the game.

The Last Embedders

OptionalTrophy: Shame On YouHardest

The hardest optional boss in the game. Found in the area way above Metropolis, accessible through the Dwellings.

Location: Area above Metropolis (via Dwellings)

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

Dr Halyn's Collector

OptionalTrophy: Rescued

Optional boss in the Vaults area. Found by going through the drawer in the large room, activating pumps, and jumping down the pipe at the end. Defeating this boss also saves Mel.

Location: Vaults area

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

Twisted Baron

OptionalTrophy: Washing Machine

Optional boss found at the end of the Manufactory area. Requires finding all 6 Fragmented Serial Numbers to access.

Location: Manufactory area

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

Dr Halyn's Experiment #223

OptionalTrophy: Maybe Knock Next Time?

Optional boss found in the Metropolis area. Located by dropping down a hidden hole on the stairs.

Location: Metropolis area

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

The Friends :)

OptionalTrophy: A Web Of Lies

Optional boss found in the Canopy area. Requires obtaining the Friends Invitation from the room to the right, then opening the door at the bottom of the drop.

Location: Canopy area

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

Intrusive Fertiliser

OptionalTrophy: Buried

Optional boss found by going down the gap to the right of the Promenade Entrance fast travel point.

Location: Promenade Entrance area

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

Sentient Pearltrap

OptionalTrophy: Cutting the Weeds

Optional boss found in the Silo area.

Location: Silo area

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

Terror of the Ledge

OptionalTrophy: Not This Time

A specific enemy found in the apartments area of the Nexus. Defeat it without taking a hit to earn the trophy.

Location: Nexus - Apartments area

⚠️ Must defeat without taking damage

Strategy Tips

  • Study attack patterns before committing to offense
  • Use your Hairpin Grapple to maintain mobility
  • Optimize your Allocation Matrix for combat abilities
  • Consider using Corrupted Boss Mode if struggling (bosses weaken after each death)

General Boss Strategy

Preparation

  • • Visit Network Gates before boss encounters
  • • Optimize your Allocation Matrix for combat
  • • Equip combat-focused modifications
  • • Consider sacrificing UI elements for more combat abilities
  • • Spend your Nacre before attempting difficult bosses

During Combat

  • • Learn attack patterns through observation
  • • Use Hairpin Grapple for positioning and evasion
  • • Chain grapple points to maintain momentum
  • • Look for safe windows to attack
  • • Don't be greedy—prioritize survival

Boss Rewards

Defeating bosses rewards you with various items and progression:

  • •
    Key Items: Some bosses drop essential keys needed for progression (e.g., Old-Fashioned Key from Calderon)
  • •
    Nacre: All bosses drop Nacre, which can be used for upgrades
  • •
    Story Progression: Defeating certain bosses unlocks new areas and story content
  • •
    Abilities: Some bosses may unlock new traversal or combat abilities

Related Guides

Abilities & UpgradesEndings GuideCollectibles