Up: That’s a mighty large robot you got there. Sadly, your “assembly” mechanic needs retooling. As is, skipping your untap step isn’t great, but that ability only costs 3 mana, and you’re probably using it on turn 7. Combine that with all the new proliferating from War of the Spark (and the originals from Scars of Mirrodin) and you have a hexproof Blightsteel Colossus that gains you 24 life on turn 7. I like the idea, but this execution is too powerful.
Unholy Collusion Sorcery Exile all creatures. If you control a Bolas Planeswalker, an Eldrazi creature, and a colored artifact as you cast ~, you win the game instead. There they stood, Bolas, Eldrazi, Phyrexians...never before had the multiverse seen such a terrifying alliance.