Looks like it was pretty easy because I forgot about the many options available for tax effects xD. My solution didn't use any leyline or cavern of souls trickery but just brute force. The legacy deck I was using was a configuration of an actual dredge deck on the draw:
Cabal Therapy away two of his counters and he should gut shot one of your creatures now (if he knows what's coming) this leaves you with 3 Zombie Tokens and he has 4x FoW in hand and 2 ornithopters on board. Cast all 4 gitaxian probes he should counter two then you get to draw to and dredge 6:
Now if he didn't counter Gitaxian Probes before (in which case you continue to dregde and set up for a win more turn 3 kill) you cast Cabal Therapy now getting 4 Zombies up to (1 Narc, 7 Zombies) Then Dread Return x2 to get through the last counter getting a minimum of 5 zombies and a FKZ he should be at 12 life (3x Phyrexian Mana 2x Force) with two ornithopers. Get in for 12 (ornithopters block 2 3/3's) putting him to exactly 0.
The modern legal version is simpler and I thought it up after I remember cards like Thalia, leyline, xantid swarm, and Grand Abolisher Exist. It's actually really simple:
I should have been more clear, it has to be vintage legal. (my solution is actually legacy legal and involves combat damage and I think there is a modern legal one aswell). I could be mean and throw in an Emrakul or somesuch but I don't think that would be as fair. Game is a normal match with 20 life and 7 card opener.
Using the vintage card pool and restricted list (ie: Vintage Legal) to build a deck that has at least a turn 3 kill against an opponent who has an opening hand of:
And draws and plays Ornithopter, Ornithopter, Memnite for his three turns and the rest of his deck are the 50 best cards in magic: Island. Game starts as usual each player has 7 cards and 20 life. You can choose to play or draw and the deck can be in any configuration of your choice (gratuitous luck), however your opponent knows this configuration and will do his best to thwart your efforts.
Bronze Tablet attempt (assuming it doesn't start in the board):
First we need an engine to flicker bronze tablet for all their lands, as a pauper player I came up with this:
Then with the help of Planar Birth all we need to do is get all of their lands into the bin.
I've conviently added an infinite mana combo the list above meaning all we need is a way to have to get all of their hand and library to the bin. Ravenous Rats looks like a good candidate for discard and Increasing confusion will do a good job for the mill.
Adding a basic land to cast each of those spells
Meaning the final configuration is:
For a total of 15 cards with a gaurenteed win on 8. Worst case scenario Cloudpost is on the bottom and you draw 8 nonland in which case you discard increasing confusion and are still fine.
Over the course of the first few turns you play out all of your permanents once you have played every permanent you begin the combo:
Mana Incoming:
Target Memnonic Wall and Cloud of Faeries with Ghostly Flicker. Return Ghostly Flicker to your hand with the wall and untap a cloudpost and an island with the Faeries this gets you 3U at the cost of 2U netting 1 per cycle gaining an arbitrary amount of colorless mana. Repeat and now untap two islands this filters 2 to U, repeat with the other lands you now have infinite 1WUB.
Removing from zones:
This time target the wall and ravenous rats to be flickered. Repeat enough times for them to discard their hand. Then cast increasing confusion = to their library. All islands are in play or in graveyard so cast Planar Birth. Activate the bronze tablet and respond to it with flicker. They are unable to pay ten life and the island is moved into your exile zone and bronze tablet is no longer considered the same object and is not exiled. Rinse and repeat for all 100 Islands.
Pass the turn, gg.
Edit: Still works with bronze tablet in the board, just add death wish to the mainboard. I don't run the ravnica bounce lands because that would mean in some configurations the game is unwinable (8 non land + bounce land).
I also found a second version that shaves off two cards:
With 0 cards in library play out all of the moxes to get WUUBG and cast wheel of sun and moon.
Cast retract floating UB. Play out the moxes again tap them for mana so you have WUUBBG play the ichor wellspring to draw retract and then cast it. Each cycle nets you 2 Mana of colors of your choice. Every third cycle play and activate a Disrupting Scepter to get rid of their hand.
This starts on their end step so after draw step I have 8 cards in hand:
Play Tropical Island and cast Reverent Silence so the top card is Greater Mossdog, or Counterbalance is destroyed.
Cast Violent Outburst and cascade into the top card of the library: Hypergenesis
Cards remaining in library: 3
Off of Hypergenesis get a Mana Echoes (from hyper genesis so it's not cast) and then Pentavus so you can float g64 colorless mana (it's a math joke). Cast kaleidostone and draw divination.
Cards in library 2:
Pop the stone cast divination and draw Merciless Eviction and Fireball. Cast Merciless Eviction on artifacts and then Fireball all Legal Targets (except yourself). Because Grip of Chaos only does single targets fireball resolves as is dealing mind destroying amounts of damage.
4x Gitaxian Probe
2x Ichorid
Phantasmagorian
Draw Golgari Grave-Troll EOT discard gorian then discard ichorids and grave troll to it
T2
Animate an ichorid using the other ichorid.
Dredge:
Cabal Therapy away two of his counters and he should gut shot one of your creatures now (if he knows what's coming) this leaves you with 3 Zombie Tokens and he has 4x FoW in hand and 2 ornithopters on board. Cast all 4 gitaxian probes he should counter two then you get to draw to and dredge 6:
1 GGT
2 Narcomoeba
3Bridge From Below
And 6 more:
Into:
Now if he didn't counter Gitaxian Probes before (in which case you continue to dregde and set up for a win more turn 3 kill) you cast Cabal Therapy now getting 4 Zombies up to (1 Narc, 7 Zombies) Then Dread Return x2 to get through the last counter getting a minimum of 5 zombies and a FKZ he should be at 12 life (3x Phyrexian Mana 2x Force) with two ornithopers. Get in for 12 (ornithopters block 2 3/3's) putting him to exactly 0.
Draw T2 Windbrisk Heights (Hideaway Titanic Ultimatum) swing for 2.
Draw T3 Plains: Swing for 27 Trample.
Using the vintage card pool and restricted list (ie: Vintage Legal) to build a deck that has at least a turn 3 kill against an opponent who has an opening hand of:
4x Force of Will
2x Mental Misstep
1x Gut Shot
And draws and plays Ornithopter, Ornithopter, Memnite for his three turns and the rest of his deck are the 50 best cards in magic: Island. Game starts as usual each player has 7 cards and 20 life. You can choose to play or draw and the deck can be in any configuration of your choice (gratuitous luck), however your opponent knows this configuration and will do his best to thwart your efforts.
(assuming it doesn't start in the board):First we need an engine to flicker bronze tablet for all their lands, as a pauper player I came up with this:
1 Mnemonic Wall
1 Bronze Tablet
1 Amulet of Vigor
1 Cloud of Faeries
3 Cloudpost
2 Islands
Then with the help of Planar Birth all we need to do is get all of their lands into the bin.
I've conviently added an infinite mana combo the list above meaning all we need is a way to have to get all of their hand and library to the bin. Ravenous Rats looks like a good candidate for discard and Increasing confusion will do a good job for the mill.
Adding a basic land to cast each of those spells
Meaning the final configuration is:
1 Mnemonic Wall
1 Bronze Tablet
1 Amulet of Vigor
1 Cloud of Faeries
1 Ravenous Rats
1 Increasing confusion
1 Planar Birth
3 Cloudpost
2 Island
1 Swamp
1 Plains
For a total of 15 cards with a gaurenteed win on 8. Worst case scenario Cloudpost is on the bottom and you draw 8 nonland in which case you discard increasing confusion and are still fine.
Over the course of the first few turns you play out all of your permanents once you have played every permanent you begin the combo:
Mana Incoming:
Target Memnonic Wall and Cloud of Faeries with Ghostly Flicker. Return Ghostly Flicker to your hand with the wall and untap a cloudpost and an island with the Faeries this gets you 3U at the cost of 2U netting 1 per cycle gaining an arbitrary amount of colorless mana. Repeat and now untap two islands this filters 2 to U, repeat with the other lands you now have infinite 1WUB.
Removing from zones:
This time target the wall and ravenous rats to be flickered. Repeat enough times for them to discard their hand. Then cast increasing confusion = to their library. All islands are in play or in graveyard so cast Planar Birth. Activate the bronze tablet and respond to it with flicker. They are unable to pay ten life and the island is moved into your exile zone and bronze tablet is no longer considered the same object and is not exiled. Rinse and repeat for all 100 Islands.
Pass the turn, gg.
Edit: Still works with bronze tablet in the board, just add death wish to the mainboard. I don't run the ravnica bounce lands because that would mean in some configurations the game is unwinable (8 non land + bounce land).
I also found a second version that shaves off two cards:
1 Amulet Of Vigor
1 Retract
1 Ichor WellSpring
1 Death Wish
1 Increasing Confusion
1 Planar Birth
1 Dirupting Scepter
1 Mox Pearl
1 Mox Sapphire
1 Mox Jet
1 Mox Emerald
1 Mox Opal
1 Bronze Tablet
With 0 cards in library play out all of the moxes to get WUUBG and cast wheel of sun and moon.
Cast retract floating UB. Play out the moxes again tap them for mana so you have WUUBBG play the ichor wellspring to draw retract and then cast it. Each cycle nets you 2 Mana of colors of your choice. Every third cycle play and activate a Disrupting Scepter to get rid of their hand.
Pool lots of mana and mill them out with Increasing Confusion and then cast Planar Birth and Death Wish for Bronze Tablet. Now with all of your mana play out amulet of vigor and bronze tablet and ichor wellspring. Activate the tablet and respond to it with retract. Repeat 100x times, that foil island is mine. Pass the turn.
Same deal as before where in the worst case you draw the 8 non mana sources in which case you discard increasing confusion.