Decklist
Approximate Total Cost:
Turn 1: Elves of Deep Shadow
Turn 2: Willowdusk, Essence Seer
Turn 3: Mischievous Poltergeist. Lose 39 life via Poltergeist and use Willowdusk to put 39x +1/+1 on Elves (or Poltergeist).
Turn 4: Rite of Consumption on Elves to gain 40 life and kill another opponent and use Willowdusk to put 40x +1/+1 on Poltergeist. Attack another opponent with Poltergeist (flying for evasion). The End.
Taking a page from my experience with Greven, Predator Captain, life loss is the aim of the game.
The basic idea is just to lose as much life in a turn as possible and then put that number of counters on a creature. There is a lot of life gain through the stats of creatures whether it checks for power or toughness.
Often there are sacrifice effects as part of that but because Willowdusk, Essence Seer can use that life gain to then put counters on another creature you gain those +1/+1 counters back immediately.
I think the contents of this deck are pretty self explanatory.
Toxic Deluge you can cast for as much life as you want and while you still have priority, before it resolves you can then use Willowdusk, Essence Seer ability to put that many +1/+1 counters on a creature meaning it will survive the Toxic Deluge.
Obviously not everybody can afford a Diamond Valley, but you know I bought one when it was about $25..so yeah the advantage of being an old school Magic player