: Major characters who are firstborn children, including Archie Andrews, Jughead Jones, Toni Topaz, and Fangs Fogarty , drop dead instantly during the reception.
: Jughead remains isolated in the bunker, writing stories to silence voices in his head. He eventually encounters his "Rivervale" counterpart, suggesting the barrier between dimensions is thinning. The Final Plague: Death of the Firstborn Riverdale s06e18
: Percival systematically inflicts horrors upon Riverdale, including rivers of blood, swarming insects, lice, and painful boils. This culminates in a literal darkness falling over the town. : Major characters who are firstborn children, including