Recently Posted Combos
Attack!
Waves of Aggression Buy + Groundskeeper Buy1. Get out a lot of creature based mana production and Groundskeeper Buy.
2. Attack with your mana producers and anything else.
3. Cast Waves of Aggression Buy.
4. This untaps all creatures that attacked, activate your mana producers for

(R/W)(R/W) then pay 
to return a land card to your hand and use the rest to retrace Waves of Aggression Buy.5. Repeat
Note that you don't need to attack with mana producers after the first time.
Patrol the Altar
Patrol Signaler Buy + Paradise Mantle Buy + Ashnod's Altar BuyCreate a soldier, sac to the altar, create another soldier and keep it. Sac every other soldier for infinite soldier tokens.
Allies United
Tajuru Archer Buy + Stampeding Wildebeests Buy + Kazuul Warlord BuyPlay Stampeeding Wildebeests, Kazuul Warlord, then Tajuru Archer. Each turn, send Tajuru Archer to your hand, then play it again. Each turn, the flying offensive of your opponent is reduced and all allies gain +1/+1.
Swamp Soldiers
Darien, King of Kjeldor Buy + Corrupt Buy + Coat of Arms Buy1: Play Darien, King of Kjeldor and Coat of Arms.
2: Play Corrupt and target yourself.
The damage you deal to yourself is healed and you get that many 1/1 soldiers; Coat of arms buffs them up: you gain as many tokens as you have swamps, with as much power and toughness as you had swamps when you played it!
Selective memory
Undying Flames Buy + Selective Memory BuyI saw someone post Selective memory and Erratic Explosion, but wanted to make it into an extended combo, even though it's almost strictly worse, so 'ere goes!
Cast Selective memory when you have 5 mana up, removing everything but, say, 2 or 3 Darksteel colossus. Draw a land, play it, cast undying flames, and swing for 11. Pow!
As far as the deck goes, be sure to play some man-lands! You might need the blockers!
Blood Withdraws
Perilous Forays Buy + Bloodghast Buy + Kalastria Highborn Buy
: put a land into play tapped, target player loses two life, and you gain 2 life.Add Amulet of Vigor Buy for insane amounts of drain
Mass Attack
Nacatl War-Pride Buy + Reconnaissance Buy + Primal Rage BuyAttack with everything, the Nacatl makes lots of tokens, and everything else you control gets through.
Controlled combat damage
Knight-Captain of Eos Buy + Militia's Pride BuyAttack with 2 non-token creatures and then pay

with Militia's Pride Buy to put in two attacking kithkin soldiers. Sac one with Knight-Captain of Eos Buy before damage is dealt and then one during your opponent's turn to prevent all combat damage. Alternately, attack with 3 non-tokens and pay 

to you gain a net one soldier during each of your turns while taking no combat damage.Trek, then Hunt, then Big Nantuko
Scouting Trek Buy + Treasure Hunt Buy + Nantuko Cultivator BuyPlay Scouting Trek Buy & put a bunch of basic land cards on top of your library.
Then play Treasure Hunt Buy & put them all into your hand.
Drop Nantuko Cultivator Buy & discard all the lands for a very large Nantuko & then draw your deck.
Also, you could use Lightning Storm Buy instead for a lot of damage & just hope they don't have a land. Or even easier, Spiraling Embers Buy. Or Countryside Crusher Buy, ok, that's enough from me.
Selective Explosion
Selective Memory Buy + Erratic Explosion Buy + Draco BuyPlay Selective Memory Buy removing everything but Draco Buy (and lands if you are a scaredy cat). Then play Erratic Explosion Buy doing 16 damage to target player. (Hint: Make sure they already have 16 or less life when you do this, it makes it easier)

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