Johnnies, all of you, behold your God, for this is possible.
First, cast Angel's Grace and Ad Nauseam to draw your whole deck. Then play a Gustha's Scepter and activate its first ability and put Lotus Bloom under it. Then, Reshape the Scepter and after it and the Lotus are put into the graveyard, respond to the second effect of reshape by casting (NOT PAYING LIFE) a Noxious Revival, to put the Lotus on top of your now nonexistent deck. Get the Lotus in play from Reshape, and play a Lotus Petal. Sac the Petal for 1 white and cast a Children of Korlis, to go back to 20 life, then sac the Bloom for 3 green and play Channel, and get 19 colorless mana (no, you can't pay life below 0 and stay alive with Angel's Grace). Use 4 of it and cast Gemstone Array. Activate the Array for 2 colorless, and get 1 white to play another Children of Korlis, gaining 38 life, and adding another 37 colorless mana to your mana pool. Use 4 colorless mana and the Array, cast Recurring Nightmare, and with the other 37 mana and yet another activation of the Array, cast a Tempt with Vengeance. From there you get a loop: Sac a token, bounce your Nightmare, reanimate Children, make a bunch of mana, sac Children, play Nightmare, repeat. Because the Children's effect is cumulative, numbers get real big, real fast. Once you run out of tokens, cast Mystic Retrieval, and play Tempt with Vengeance again. Once you run out of tokens for that, flashback the Retrieval and play Tempt a third time. Keep making mana until you run out of tokens, and use Array and the insane amount of colorless mana, cast a Banefire directly at your opponents face. The number is too long to even write out, but it has 6 million digits, or somewhere close to that.
You're welcome.