The Mengucci video that was just posted was really great but 3 Karn Scion of Urza seems overkill. With taking out Cloudposts he had a chance to run Goblin Welder with Great Furnace in there. He also could have cut a Voltaic Key as 2 seems to me to be too many. With that he could have played another Trinisphere. Walking Ballista is really powerful as removal but it's not much of a threat and the deck can win by slamming down a Wurmcoil or a Lodestone or a Forgemaster so I don't think it's needed. This is what I would run inspired by his list, not tested but I'm excited to try it out

4 Great Furnace
4 Cavern Of Souls
4 Wasteland
4 City of Traitors
4 Ancient Tomb
2 Darksteel Citadel
4 Metalworker
4 Grim Monolith
4 Chalice Of The Void
3 Trinisphere
1 Lightning Greaves
1 Staff Of Domination
4 Goblin Welder
1 Karn Scion of Urza
1 Sundering Titan
3 Wurmcoil Engine
4 Lodestone Golem
3 Kuldotha Forgemaster
1 Blightsteel Colossus
1 Platinum Emperion
1 Voltaic Key
1 Ensnaring Bridge
1 Crucible of Worlds