Lethal Vapors an arbitrarily large number of times.
Cast
Teferi's Protection by paying ({2} magic symbol) ({W} magic symbol) : until your next turn your life total can't change and you have protection from everything.
Allow all the activated abilities from
Lethal Vapors to resolve, skipping an arbitrarily large number of turns.
Results
Skip all of your future turns, causing your opponents to eventually draw from an empty library and lose the game.