Undertale Soul OPs 2 Beat Gaster — Multiverse Malfunction Boss Guide

Gaster is the capstone boss of Normal Mode’s Multiverse Malfunction arc in Undertale Soul OPs 2. After Outertale Asgore falls, the arena fractures, clones multiply, and the fight shifts from standard lane defense into a mechanics check: identify the real Gaster, land 50 hits to stun, then throw souls at the Universe Core through six distinct movement phases. Teams that master this fight unlock Endless Mode access and can chase the secret Dio Sans coffin (Secrets). Weak soul defense before this point — see Defend Souls — guarantees a loss here.

Phase overview

Gaster breaks into three repeating loops until the encounter ends:

1. Clone swarm — multiple Gasters spawn; only one is real
2. 50-hit stun window — focus fire the real clone before fakes reset
3. Universe Core soul throws — six movement phases requiring aimed throws at the core while dodging hazard lanes

Between loops, standard AU trash may leak toward souls. Keep one Defense player on anchor duty per Team Comp Checker recommendations.

Universal Malfunction and Gaster fight

Identifying the real clone

Fake Gasters mimic animations but differ subtly in attack cadence and damage taken. Community-tested tells (patch-stable as of recent builds):

• Real clone takes full M1 damage; fakes sometimes rubber-band HP
• Real clone telegraphs the bone-rail attack toward players, not souls first
• After a few seconds, fakes flicker or desync movement if you kite them

Assign one shot-caller: “left real” or “center real.” Five players splitting on fakes wastes the stun window. Attack-class ults on R (Controls) dump here — coordinate voice “3…2…1… R”.

The 50-hit stun mechanic

Once the real clone is tagged, the team must land 50 combined hits (any mix of M1 and abilities) before the stun timer expires. Failure resets clone phase with heavier soul pressure.

Stun tips:

• M1 chain during stun — do not reload shop perks mid-window
• Hold Q/2 if they add hit-count ticks faster than M1 alone
• Do not chase fakes off the soul ring — one leaked wave during stun often chips two souls

Perfect-wave streaks (Economy) often die here; accept one soul chip over a full wipe if your Support is dead.

Universe Core — six movement phases

After stun, Gaster exposes the Universe Core. Players must throw souls (interact + aim) at the core while it moves through six phases of patterns. Console players should use LT shift-lock from Controls for throw aim.

Phase behavior summary:

Phase	Core behavior	Team focus
1	Slow orbit near center	Calibrate throw arc, clear stray trash
2	Lateral sweeps left/right	Pre-position souls before sweep returns
3	Vertical bob + feint stops	Delay throw until bob peaks
4	Accelerated figure-eight	Call “throw now” — no solo heroes
5	Outer ring dash	Outer Attack players intercept adds
6	Core holds center briefly	Burn R ultimates, max throw damage

Missing a required throw in phases 4–6 usually damages souls and extends the fight into enrage-style trash waves. Review Normal Walkthrough if you arrive under-geared — Tier 3+ (Tier Unlock Planner) smooths DPS checks.

Recommended team comp

Ideal five-stack:

• Two Attack — clone DPS and phase 6 burst (Sans, Undyne per Tier List)
• One Defense — soul anchor during throws (Toriel, Asgore)
• One Support — heal spikes between phases
• Flex — second Support or hybrid if lobbies lack healing

Four-player lobbies: buy turret covering the lane you leave during throws (Economy).

Gear and economy before Gaster

Each Tier upgrade costs 1,250 coins to max Tier 5. Entering Multiverse Malfunction at Tier 1 is viable for learning, but pug clears expect Tier 2–3 on mains. Farm UT and Underfell arcs with perfect-wave discipline (+25 per clean wave).

Badges from earlier clears may unlock throw-buff perks (Unlock Characters) — equip before queue.

After Gaster: Endless and secrets

Defeating Gaster completes Normal’s main arc. You can enter Endless Mode (Endless) for scaling farms or hunt the Dio Sans coffin secret (Secrets) if your lobby knows the trigger.

Hard Mode (Hard Mode) replaces mid-run arcs but still tests soul defense — do not jump Hard until Gaster feels repeatable.

Practice checklist

1. Read clone tells in a learning lobby — skip dialogue vote only after first clear (Controls)
2. Drill 50-hit focus with friends — no random R during trash
3. Assign throw caller; rehearse shift-lock on console
4. Map each Universe Core phase to a callout word
5. Review Defend Souls if souls die during phase 4

Common wipes and fixes

Problem	Fix
Cannot find real clone	Mark first target that takes sustained M1; stop swapping
Stun expires early	Stack Q/2 hit-count; skip shop between clone spawn and stun
Souls hit during throws	Anchor Defense holds inner ring; Attack returns after throw
Phase 5 adds overwhelm	Save one turret charge for outer dash
Low DPS	Tier upgrades + Tier List picks; avoid Scripts reliance

Gaster is the skill gate OyunKlavuzu designed before Endless scaling — respect the six phases and the run becomes farmable.