NLRP3's full name literally has "pyrin domain" baked into it (the PYD-PYD handshake between NLRP3 and ASC is the first domino), so the demon gets named after its own trigger mechanism. Doom does this constantly anyway (Cacodemon, Arachnotron) — Greek/Latin-root flex names for biology terms nobody questions.

Class: heavy, sits in Hell Knight/Mancubus weight class, not Marauder-tier rare.
HP: ~480, roughly a notch above Hell Knight.

Phase 1 — dormant. Slow, armored, melee-only, boring on purpose. This is the "unprimed cell" state — it just absorbs hits and doesn't do much back, which baits players into ignoring it in a crowd. Mistake.

Phase 2 — primed. This doesn't trigger off one big hit, it triggers off sustained pressure within a damage window — meaningfully different from a normal stagger threshold, because it's modeling priming as a transcriptional buildup, not a single signal. Once it crosses that line, plates crack open down the chest, veins light up under the armor, and it gets meaningfully faster and starts lobbing a ranged attack — small bursting clusters that leave a caustic pool, your IL-1β stand-in. It's now a worse problem than it was a second ago, on purpose, because that's literally what happens biologically once NLRP3 finishes assembling.

Phase 3 — assembled (the money shot). Specific trigger — say, plasma or precision damage, standing in for the actual "signal 2" inputs like K+ efflux or ROS rather than generic damage — forces the chest fully open and exposes the core you're looking at in the render. ~4 second window, 3x damage multiplier on that one spot, miss the window and it folds back to phase 2 with the priming clock only partially reset, so you don't get infinite free pokes.

On death — pyroptotic rupture. This is the part I'd actually build the encounter around. It doesn't really hurt you when it pops, but it primes every demon in the blast radius, fast-forwarding their phase-2 clock. Real biology backs this harder than you'd expect — ejected ASC specks can seed new specks in neighboring cells, it's almost prion-like propagation, not just a metaphor I'm stretching. In-game that means popping one mid-crowd is a deliberate tactical choice, not just "kill the glowy guy" — sometimes you want to bait it off to the side first, sometimes you want to detonate it into the pack on purpose for a high-risk chain reaction.