End of Abyss Suit Mods: All 10 Mods, 8 Vaults & 6 Energy Cells

Suit Mods are End of Abyss’s passive-equipment system — rings, essentially: each mod grants a passive effect while equipped, and each Energy Cell you find adds one slot. The economy tying it together is Vault Keys — five drop from story bosses, three from the optional bosses — and they open the eight Vaults holding most of the collection.

How the system works

• Vault Keys: Husk Cluster, Centipede Husk, Security Sentinel, Drowned Husk, Radiation Host (story) + Centipede rematch, Brood Keeper, Morgue Dweller (optional). Eight keys, eight vaults.
• Energy Cells: six hidden pickups; each = +1 mod slot. All six earn the “Fully Suited Up” trophy.
• All eight vaults: the “Dungeon Crawler” trophy. Nothing is missable.

All 10 suit mods

Mod	Effect	Location
Vitality Enhancer Mk. I	Max health up	Starting mod
Radiation Protection	Blocks ambient radiation damage	The Basement under Factory East — story pickup (part 5)
Equipment Belt	Extra equipment capacity	Vault — Habitation F1, end of the hall
Vitality Enhancer Mk. II	Bigger max health up	Vault — Communication Center F2: right-side lift down, door right, trap door (after the 3 SCUs)
Heal Amplifier	Stronger healing	Vault — Reactor B4, top-left corner
Blast Resistance	Reduced explosive damage	Vault — Factory West F2, left side (Explosive Charge wall)
Acid Neutralizer	Blocks acid damage	Vault — Waterworks B3, in the drained pit after the switch+pump sequence
Proximity Sensor	Warns of nearby threats	Vault — Containment F1 bottom-right: burn the Parasitic Growth, ladder down (Incinerator)
Auto-Defibrillator	Survive a lethal hit	Vault — Infirmary B1, left side
Experimental Core	Prototype passive	Vault — Lower Levels F1, needs Level 3 Access

The Level 2 and Level 3 Access cards

The Experimental Core vault is behind Level 3 Access — a two-card chain inside Lower Levels F1:

1. Level 2 Access: burn the wall on the right side of F1 with the Incinerator, enter the large room, drop through the trap door in the middle, exit the vents, head right — the card is on a corpse.
2. Level 3 Access: through the door just south of the burnable wall on F1, up the stairs, through the corridor, exit left then left again — top-left corner of the room.
3. The vault sits behind the right-side door on F1.

All 6 Energy Cells

#	Location	How to reach it
1	Maintenance > F2	Large chest in plain sight — on the part 3 path
2	Factory West > F3	Explosive Charge the wall left of the bridge switch, then a second charge on the hall’s left wall
3	Habitation Sector > F2	Burn the F1 left wall → Block A Keycard → F3 vent route → Explosive Charge floor → Janitor Key → Block B room
4	Reactor > B3	Ladder in the top-left corner of B4
5	Waterworks > B3	Grappling Hook the switch above the door
6	Containment Sector > F2	Destroy the petrified worker — shoot or melee it

Priorities: Cells 1 and 2 sit almost on the critical path — grab both before the Containment Sector, because Radiation Protection eats several slots at once and you’ll want real mods underneath it. Cell 3’s Janitor Key chain is the longest detour; pair it with Data Shard 2 on a Habitation sweep.

Recommended loadouts

• Story progression: Vitality Mk. I + Radiation Protection when required + Equipment Belt.
• Boss attempts: Vitality Mk. II + Blast Resistance + Proximity Sensor — awareness beats greed in fights like the Fractured Being.
• Post-game cleanup: Auto-Defibrillator for risky optional bosses + Proximity Sensor for ambush rooms.

Kit context: weapons overview · full checklist: logbook completion.