Eldrazi Summoning Trap (Modern)

The concept of the deck is to ramp up Mana through Lotus Cobra, Llanowar Elves, Birds of Paradise, Harrow and Garruk Wildspeaker to get 6 Mana so you can cast Summoning Trap. Since we have 9 big creatures, the chance of hitting one is extremely high. Once an Eldrazi comes out (mostly in turn 3 or 4) the game is pretty much over.

Mana Ramp cards: Llanowar Elves, Birds of Paradise, Lotus Cobra, Harrow, Garruk Wildspeaker, Evolving Wilds (in combination with the Lotus Cobras)

Tutors: If you don't get your Summoning Trap, there's always the possibility for the Diabolic Tutor or Liliana Vess

Big Creatures: It that betrays, Ulamog, Kozilek, Emrakul, Artisan of Kozilek, Pathrazer of Ulamog, Darksteel Colossus (You can swap these out as you want, i just really like Eldrazi and Darksteel colossus)

It's a pretty straightforward deck, since even if you are unlucky with the Summoning trap or one big creature gets taken out, you get so much Mana through the Ramp that you can hardcast any Creature from turn 5 onwards.

This deck is pretty strong against most decks, since it doesnt take long to ramp. It even works well against Blue/Counter since Summoning Trap doesnt cost anything if something got countered.
It struggles a bit against Exile cards and pure early agression like elemental decks.

Downside is, it's not that cheap of a deck through the Eldrazi and you might lose a few friends for playing something that nasty.