Herald of Anguish + Metalwork Colossus. This is a slightly control-focused mid-range Colossus deck that looks to get huge threats on the field but with enough interaction to buy time to get the big guys in. Mix of hand control and creature removal to combat popular meta builds GB, Copycat and Mardu Vehicles with many options in sideboard.
Card Choice breakdown:1-Cost Artifacts: Control elements to mitigate against certain strategies, easily side-boarded against others. Implement of Combustion breaks Copycat, hits Mimics, and takes out Motorists with the additional benefit of hitting Revolt for Fatal Push. Pacification Array works well against big threats until they can be permanently removed, especially good against GB in mid-game.
2-4 Cost Artifacts: Card draw and mana fixing and ramp. The 2-costers draw cards, as does Hedron Archive. The prism and caravan are important for the red splash of Unlicensed Disintegration. The caravan can also be crewed on the turn a creature is played - this is especially important against slower attrition decks or when dropping multiple Colossi at once. Key to the City allows card draws as well after improvising, and 10/10 unblockables will win the game.
Creatures: Only biggies. Colossus can come in by turn 4, as can Herald. Colossus often comes in pairs or in triplets thanks to Sanctum of Ugin, and Inventors' Fair can dig for one if one is not readily available. A single Reality Smasher is unexpected and powerful, especially against control.
Control Spells: ten in mainboard include seven hard removal spells, one Grasp and two Transgress. This can be greatly augmented by the sideboard. Unlicensed Disintegration is among the best removal in the format and works especially well against Copycat builds and Nissa, though when paired with Implement of Combustion will also do nicely for taking out a Gideon. Ruinous Path goes the rest of the way in protecting against planeswalkers.
Sideboard: Some creatures in the form of Scrounger and the Thopter to play against control, Flaying Tendrils against zombies, tokens, and Mardu vehicles, Harsh Scrutiny for elder deep-fiends and other problematic creatures and To the Slaughter especially for Bristling Hydra which is prominent in my meta.
+1 upvote if you think this works!