This deck takes the traditional Tron strategy of slamming 7-drops and augments it with Karn, the Great Creator. Here's how the combo works:

1) Play Karn, and use the -2 ability to grab Mycosynth Lattice.

2) Play Mycosynth Lattice. Now all of the opponent's lands are artifacts, and thanks to Karn's passive ability, they can no longer tap for mana. The opponent can never cast another spell.

Note that if they have creatures in play, they can still attack Karn, but if the coast is clear then this combo ends the game. Karn can also fetch silver bullets (fitting, for a silver golem), which are cards that hose opposing strategies. For example, Chalice of the Void can lock out 1-drops, Ensnaring Bridge can stop creatures, and so forth.

What Karn adds to this deck is a cheaper play that also threatens to end the game, and against some decks, just having Karn, the Great Creator in play really cuts off their options. Affinity and Hardened Scales hate playing against Stony Silence, and even in the mirror, Karn has a huge effect.

War of the Spark is shaking up every Constructed format, and there are some can't-miss cards when it comes to building decks. My top five recommendations are:

Blast Zone
Karn, the Great Creator
Teferi, Time Raveler
Narset, Parter of Veils
Liliana, Dreadhorde General

All of these cards are seeing a ton of play, and Blast Zone and Narset in particular are making an impact across formats. Pick these up now and you'll be well-prepared for wherever the metagame goes next!