Stiflenought is a tempo-combo deck that wins by using Stifle to counter Phyrexian Dreadnought's triggered ability, landing a free 12/12 trample, and protecting it with counterspells. Your game plan is to ignore their threat and go wide with tokens and mana elves, outpacing their single threat with sheer board presence — Deranged Hermit's squirrels are particularly good here since a 12/12 can't block them all profitably. Wirewood Symbiote is excellent for bouncing Multani's Acolyte to refuel through their counterspells, and Survival of the Fittest gives you a resilient tutor chain they must answer. Biorhythm comes in as a win condition that bypasses combat entirely — once you have a large board, it reduces each player's life total to their creature count, which your elf swarm should dominate decisively. Board out the lone Naturalize since they have minimal relevant artifacts or enchantments in the main, and Powder Keg in their sideboard can be addressed with the Nantuko Vigilantes you're keeping in.