Explosive Singularity and Triumph of the Hordes in hand.
({10} magic symbol) ({R} magic symbol) ({R} magic symbol) ({G} magic symbol) ({G} magic symbol) at most available.
Steps
Cast Triumph of the Hordes by paying ({2} magic symbol) ({G} magic symbol) ({G} magic symbol) , giving creatures you control +1/+1 and infect until end of turn.
Cast Explosive Singularity by paying at most ({8} magic symbol) ({R} magic symbol) ({R} magic symbol) , dealing 10 damage to any creature.
Imodane triggers, giving each opponent ten poison counters.
Each opponent loses the game as a state-based action due to having ten or more poison counters.