This Colorless Prison/Ramp deck wants to lock you out with pieces found off Karn, the Great Creator (which shuts down opposing artifact activated abilities) while assembling Urza's Tron for Ugin, Eye of the Storms or other threats. Pithing Needle can name Karn, the Great Creator to stop its +1/-2 activations, or name a problematic land like Urza's Saga to slow their artifact assembly. Feed the Swarm gives you a way to remove Karn, the Great Creator once he resolves, since your deck otherwise struggles to interact with planeswalkers. Grafdigger's Cage is mostly dead here since their threats are cast rather than reanimated, but it's a low-opportunity-cost artifact that can still matter incidentally; the small cuts come from redundant cantrip/mana pieces that are less impactful in a grindier matchup.