Right now it looks like your deck is having a hard time to actually win games thanks to the no-combo-policy. Well we just have to go around it.

So, bigger and badder creatures: Darksteel Colossus, Blightsteel Colossus, Karn, Silver Golem, Wurmcoil Engine for example.

Artifacts (+white&blue) have great ways for taxing people. You could fix your early game "iffynes" by playing cards that slow the game down enough for you to hit the big boys on the field. Cards Like: Lodestone Golem, Trinisphere, Ethersworn Canonist, Winter Orb, Tangle Wire etc. You can play around Winter Orb by increasing the amount of mana producing artifacts: Grim Monolith, Basalt Monolith, Mana Crypt, Mana Vault, Coalition Relic, Worn Powerstone, Mox Opal, Gilded Lotus etc. Note that in the end game they won't be useless as you play Tezzeret the Seeker (& Karn, Silver Golem & March of the Machines).

I suggest you alter your game plan to ramp artifact mana and slow the game down with tax cards in the early game and finish the game with big artifact creatures and/or hordes of animated artifacts. General damage is an option too although without pump cards such as Cranial Plating she has to hit 5 times to kill someone.

Also: Copy Artifact, Memory Jar and some other cards I can't remember at this point.

I hope this post will prove useful for you. Cheers :)

Maybe consider soulscour; it certainly is expensive, but considering most of your permanents (some lands) are artifacts, it would probably swing games to you.

Just a thought; try it out if it interests you.

@caseyFermi1: I considered it a while ago (as well as Scourglass ), but I felt that it would hurt this deck a lot, considering it tends to be quite mana-hungry later in the game. I would consider Nevinyrral's Disk before either of these.

Update: added Open the Vaults and Voltaic Key to my maybeboard, what do you guys think?

1 thing u missed that i think would be great Disciple of the Vault Phyrexian Metamorph and sharum=instant win

@kartzzy: Originally, I had the disciple in the deck, but I took him out as I found him to be rather underwhelming, as he doesn't do much apart from being a combo piece. Bitter Ordeal 's countermagic resistance and Glassdust Hulk 's cycling make them more appealing to me. :/

Extractor Demon is in the same boat as Disciple, except my meta has a few too many Eldrazi to make it worth the effort.

yea i feel u i run 1 copy of Ulamog in most of my EDH decks