Storm King's Thunder by paying ({9} magic symbol) ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) , copying the next instant or sorcery spell you cast nine times.
Cast
Vraska's Fall by paying ({2} magic symbol) ({B} magic symbol) .
Storm King's Thunder triggers, copying
Vraska's Fall nine times.
Resolve each
Vraska's Fall, causing each opponent to get ten poison counters.
Each opponent loses the game due to having ten or more poison counters.