It's a nice deck but there are some suggestions that I do want to make that might help you in the long run.
Firstly As far as creatures go I'd recommend sticking to the eldrazi but keep the creatures in the deck that either have FIRST STRIKE and/or DEATHTOUCH. If a creature with death touch does not have first strike then add
sure strike and
kindled fury to this deck. They will give your creatures first strike AND since they're red instances your
guttersnipe's effect WILL trigger. Also by adding
dragon fodder or
goblinslide to this deck you can make goblin tokens and sac them using
collateral damage to deal even more damage. If you add the eldrazi or other creatures that make scion tokens upon death like
carrier thrall then you can play cards like
bone splinters and not only get rid of a creature but also get ANOTHER CREATURE. Have two
impact tremors on the field and a
molten nursery and you've got yourself a
dangerous deck.
Secondly you should try to remove the mana sinks from your deck. When I say MANA SINKS I'm referring to the creatures that make you spend extra mana just to use their abilities and the high drops that have steep costs just to play them with minimum
profit from them being played. Adding more cards like
silent skimmer and
dominator drone will really put your opponent on edge cause no matter what you do they are going to take some damage. Take out the sliver, the shade and
the brute who has to attack every turn and replace them with cards like
splatter thug,
titan's strength, and add more guttersnipes to your deck. Also add
forerunner of slaughter to this deck to make the eldrazi creatures faster.