Shi Maria's manifestation through Carl in the Lemig ballroom, slaughtering goblins and maddening the survivors.
When Mordecai's potion and Commander Stockade's spell hit at once, Carl convulsed, went fully corporeal, and became Shi Maria in a single blink. The spider roared "I have always loved you" and lashed out with her front two arms; Lemig Goblins separated from their bodies as she rampaged, screaming that she never killed Hapanzi and ripping a goblin in two for suggesting she'd hurt him. Luke threw himself in front of the cowering Stockade and lost his legs.
Then her eye opened and the Insanity spell lit the room in prismatic light. Surviving goblins shot, stabbed, and bit each other; one finished the crawling Luke and then cut his own throat. Shi Maria collapsed, legs jumbled, and blinked out — the blood coating her falling over the restored Carl like a dumped bucket. The massacre becomes the Minor Quorum's evidence, kills Stockade by delayed madness, and ultimately collapses The Ceasefire.
The atrocity at the center of the inquiry and the proximate cause of the war's early start.