Prism Cluster

What it is

A geometric refractor encounter built around four equal-share crystal gems arranged at the cardinal points of the arena. All four gems share a single boss bar in 25% slices; the lead gem is the visible bar anchor while the other three sit on the same shared health pool. Each gem fires its own arena-spanning sweeping beam, with the four sweep phases offset by 90 degrees so the beams interlock into a rotating refractive pattern that the player navigates between.

There is no shielded gate, no body-swap phase, and no pressure adds — the entire encounter is “stay inside the moving safe wedges between four sweeping beams while shooting down the gems one at a time.” Each gem death plays a per-gem color burst and visibly snaps the rainbow lattice that connects the survivors, and the final gem detonates an arena-wide rainbow cinematic.

The encounter is tagged for the mini-boss pool. It also runs as the final boss when randomly drawn from the boss pool — the same authored roster scales up via the mini ×4 or boss ×8 stat multiplier.

Identity

FieldValue
ThemeGeometric refractor — four crystal gems anchored at the compass points
PaletteCitrine yellow, ruby red, jade green, pearl white, with a white-bloom shared accent
Pool kindmini (eligible for both mini-boss and final boss slots)
Composition4 sharing bodies (one per cardinal point), no anchors, no adds
Bar anchorCitrine gem (the north point in roster order)
Bar colorPearl white
Roster body AIorbit_center (each gem orbits the arena center)
Affixes on bodiesnone
Abilitiesone Prism Beam Sweep per gem (Citrine, Ruby, Jade, Pearl)

Arena

FieldValue
Shapecircle
Radius400 world units
Terrain patternopen
Arena closing duration8 seconds

The arena radius doubles as each gem’s beam length — the beams sweep all the way to the arena wall, so there is no safe “stand in the back” range. The four gems are placed by the arena helper at the cardinal points (angles 0, 90, 180, 270 degrees), one per compass direction.

Body composition and HP

BodyCountHP per bodyShare poolTargetableNotes
Citrine gem11500yesyesbar anchor; HUD reads its display name
Ruby gem11500yesyessharing body
Jade gem11500yesyessharing body
Pearl gem11500yesyessharing body

Total bar pool: 6000 HP distributed across the four bodies in equal 25% slices. Damage to any gem drains the shared bar; a gem dies when its individual 1500-HP slice is depleted, at which point its beam stops firing and its lattice connections snap to the survivors.

Phases and damage gates

RuleTriggerEffect
All gems vulnerable from startencounter spawnno shielded gate; every gem takes damage immediately
Per-gem death cinematica gem’s 1500-HP slice emptiesgem despawns, its beam ability stops, lattice lines touching it snap, sparks recoil toward surviving gems
Encounter end cinematicfinal gem’s slice emptieswhite-out flash, rainbow shockwave stack from arena center, arena-wide shard burst

The fight has no HP-threshold phase transitions and no scripted body swap. The 4→3→2→1 gem count is the entire phase structure — fewer surviving gems means fewer beams in the air, so beam density falls off as the fight ends.

Abilities

Each gem fires its own instance of the same beam-sweep pattern. The four instances share every parameter except color tint and starting rotation phase, which are offset by 90 degrees per gem so the four sweeps form an interlocked pattern as they rotate together.

Prism Beam Sweep (per gem)

FieldValue
Patternbeam_sweep
Cooldown3.5 seconds
Start delay (first cast)1.0 seconds
Telegraph duration1000 ms
Sweep arc120 degrees
Sweep duration600 ms
Damage per second on contact40
Beam lengthfull arena radius (400 world units)

Per-gem color tint and start-phase offset:

GemBullet colorStart phase offset
Citrinecitrine yellow0 degrees
Rubyruby red90 degrees
Jadejade green180 degrees
Pearlpearl white270 degrees

All four gems share the same 3.5-second cooldown clock, so they fire together — the 90-degree phase offset is in the starting rotation angle of each sweep, not the firing time. After a 1.0-second cast delay on first encounter spawn, the four telegraphs paint together for 1000 ms, then the four 120-degree arcs sweep over 600 ms in their offset phases. Contact damage is dealt as 40 damage per second, so the bite from a single grazing pass is much smaller than the bite from standing inside a beam for its full 600 ms sweep.

Spawn profile

FieldValue
Profile idnone
Wave count0

Prism Cluster is the only shipped boss with a none spawn profile. The four-gem sharing roster is the entire encounter pressure — no orb dribble, no gunner walls, no cardinal pushes. The fight is intentionally about reading the four sweeping beams, not about juggling adds.

Rewards

Reward typeValue
XP on kill800
Currency on kill80
Extra level-up reward picks granted1
Cascade ring compositiondefault 5-prop ring (2 scrap pile, 1 mineral, 1 comet fragment, 1 magnetar pulse)

The XP and currency payouts are the highest in the shipped roster (800 / 80 versus Killer Croc’s 500 / 50), reflecting the encounter’s higher mechanical demand — four simultaneous beams with no shielded checkpoint and no escape into add-management. The reward cascade is the engine default; no per-boss override is set.

Scaling

Prism Cluster is a mini-pool boss. The authored stats above are the level-1 baseline. The encounter is scaled at spawn by the boss tier multiplier and the run-depth ramp:

SlotTier HP multiplierTier damage multiplierReward chamber cascade rings
Mini-boss appearance4.04.01
Final boss appearance8.08.02

Depth ramp on top of the tier multiplier is 1.0 + 0.5 × (currentLevel - 1) / (totalLevels - 1), applied to both HP and damage.

SlotDepth multiplierCombined HP (full bar pool)Combined beam damage per second
Normal mode L3 (mini)1.50×6.00 (36000 bar pool)×6.00 (240 per second per beam)
Challenge mode L3 (mini)1.22×4.89×4.89
Challenge mode L6 (mini)1.56×6.22×6.22
Challenge mode L9 (mini)1.89×7.56×7.56
Final-boss draw, last level of run1.50×12.00 (72000 bar pool)×12.00 (480 per second per beam)

In addition, every boss inherits the default per-level scaling curve (hp ×2.0/level uncapped, damage ×2.15/level uncapped, plus soft/hard caps on fire rate, move speed, projectile speed, sweep speed, spawner frequency, effect radius, and enrage timer) starting from the player’s currentLevel at encounter spawn.

EXTRACT-CANDIDATE flags

  • The mini ×4 / final ×8 tier multipliers and the depth ramp formula are duplicated from mini-bosses.md and from the Killer Croc page. Acceptable per the wiki “tables can duplicate” rule — kept here so the per-entity page is readable standalone.
  • The default boss scaling curve (per-level multipliers, cap behavior, base enrage timer) lives in data/boss-scaling.ts and is shared by every boss. Currently not documented on a canonical scaling page; recommend extracting to a bosses/scaling.md or extending bosses.md once all 8 entity pages exist, and replacing the trailing scaling paragraph here with a link.
  • The beam_sweep pattern is shared with other bosses but not yet documented on a per-pattern catalog page. The arena-radius beam-length sentinel (where beamLength=0 resolves to arena.radius() at fire-time) is a pattern-runtime detail that belongs on an abilities-internals page rather than this entity page.
  • The “share pool in equal slices” multi-body composition is the only example of a roster where every body is a sharing body with no anchors and no boss/non-boss asymmetry beyond the bar anchor flag. If a wiki page on boss composition patterns is broken out, Prism Cluster is the canonical example for the “equal-slice ring” pattern; Killer Croc is the “shielded singleton + anchors” pattern.
  • The none spawn profile is shared in concept but Prism Cluster is its only current user across the shipped roster. Worth flagging on bosses.md as the “no-adds reference encounter” since the design intent (mechanical density via beams instead of adds) is load-bearing.
  • The per-gem death cinematic (palette-tinted shard burst, additive spark burst, screen tint pulse, camera zoom pulse) and the lattice snap-and-recoil are visual layers handled by the boss VFX kit. Not documented on the entity page beyond a brief mention because the kit is shared across bosses; belongs on a boss-vfx-kit.md page if/when broken out.