Lots of big creatures to take advantage of Xenagos' ability as well as lots of effects to create multiple combat steps or copy triggered abilities allowing Xenagos to be even more effective. I hate lands so I only run 30, ramp is better than lands anyway so it should be made up for by the number of ramp spells in this deck (11 if you count GSZ searching for Dryad Arbor). Seriously though, fuck lands.
Savage Beating is probably the best card in the deck, allowing a creature do deal 12 times it's damage in one turn with Xenagos on the board, this usually ends the game.
Deus of Calamity
Terra Stomper (maybe)
Avatar of Slaughter (maybe)