Final answer:
In 'Scythe' by Neal Shusterman, Rowan killed Goddard by poisoning the wine at a scythe conclave feast.
Step-by-step explanation:
In Neal Shusterman's book Scythe, Rowan Damisch killed Scythe Goddard in a dramatic turn of events. This takes place at a scythe conclave, specifically during a feast when Goddard and his followers are gathered. Utilizing a ring containing a poison gifted by Scythe Curie, Rowan taints the wine, leading to the demise of Goddard and others who drank the poisoned beverage. It's a pivotal moment in Rowan's transformation within the narrative, marking a significant shift in his character's journey and the overall plot of the novel.