Angel's Grace (Or Platinum Angel, if you've got the goods), Ad Nauseam, 4x Semblance Anvil (Sac 4 Ornithopters + 4 mana total to cast all 4) = So much free stuff!!
You could potentially sac an Instant for 1 Semblance Anvil as well, so that you can complete the Angel's Grace / Ad Nauseam combo sooner.
The setup
Ideal Lands to have in play for maximum effectiveness: 2 Mana Confluence, 1 Urza's Tower, 1 Urza's Mine, 1 Urza's Power Plant
Artifacts on the field: At least 1 Chromatic Lantern, and 1 Semblance Anvil would be amazing at "killing" time.
1 White to cast Angel's Grace, - Tap Chromatic Lantern, 2 Black + (3) to cast Ad Nauseam - Tap
Urza's Tower
and 2x Mana Confluence (with Chromatic Lantern on the field, this will NOT cost you any health (not that it will matter in a second)), and if you sac'd one instant to Semblance Anvil, this would leave you with (2) in your pool, and help you combo faster.
Best hand to have when going for the kill would include Angel's Grace, Ad Nauseam and at least 1 Pact of Negation (you won't have to worry about that "you lose the game" stuff). It would also be best to wait for your opponent to tap too many lands on their turn to be able to do anything about it, but in the event that they leave some to attempt to counter you, that's why I recommended having Pact of Negation in your hand.
Chain goes as follows: Angel's Grace, Ad Nauseam and empty your entire library into your hand. At this point you will have 3 - 4 Pact of Negation in your hand, which should be way more than your opponent can handle. Cast Spellbook x2, Cast Semblance Anvil (if you have (2) in your pool, this will cost you (1), sac Ornithopter, repeat 1 more time for (1) (Leaving you with (1) in your pool), then once more for FREE. Now every artifact and creature in your hand will cost (6) less to cast!!! Cast the other 3x Chromatic Lantern for FREE, cast all 4x Prophetic Prism for FREE, cast all 4
Plague Myr
for FREE, cast your 1 Ornithopter for FREE (well...), cast Akroma's Memorial for the (1) already in your pool and instantly get (4) from your Myr's thanks to their newly acquired Haste, then get (3) from your new Chromatic Lanterns Use (1) + (1) to cast 2x Platinum Angel (casting at least 1 IS VERY VERY IMPORTANT!!!), use (3) to cast Darksteel Forge, then use the remaining (2) to cast 1x
Ulamog's Crusher
, who has haste, amongst a bunch of other new abilities, and instantly cost your opponent 2x permanents (and 8 life, to boot). Feel free to attack with your Platinum Angels as well, as long as you're confident that your opponent CANNOT remove either from play. These are the ONLY THINGS KEEPING YOU ALIVE FOR THE REST OF THE GAME!If you played your cards right, you should have at LEAST 2x Pact of Negation to take care of any problem spells your opponents may cast on the following turn. Finish it off in the next turn, where you will have a RIDICULOUS amount of mana to play with, and your opponent will not be able to do anything about it.