14. PJim: Leyline of the Void, Maze of Ith, Icatian Store, Karn Liberated
I didn't want to lose to Bombardment, and I didn't want to lose to Leyline, which left my options feeling pretty limited.
Against all the Bombardment decks I need to restart the game twice, having stolen Bombardment first time so you can't hide your creatures from Karn. Fortunately that doesn't appear to be more complicated in any matches I see.
vs
1. Asthereal (TO): Plains, Mishra's Factory, Giant Killer, Swords to Plowshares // 6-0, Plenty of time to resolve Karn
2. Wrath of Pie: Taiga, Mishra's Factory, Young Wolf, Goblin Bombardment // 6-0, Plenty of time to resolve Karn
3. Reeplcheep: Crystal Vein, Arcbound Ravager, Clockwork Beetle, Leyline of the Void // 6-0, Maze handles Ravager
4. alphastryk: Leyline of the Void, Unmask, Subterranean Hangar, Shriekmaw // 2-2, Unmask takes Karn, Maze handles Shriekmaw.
5. dte: Tarnished citadel, Death's shadow, Tinder Wall, Lodestone golem // 6-0, Fortunately you need Wall twice for Golem, so Maze handles Shadow.
6. Phasmoid: Phyrexian Walker, Swamp, Culling the Weak, Mana Skimmer // 6-0, Maze handles it.
7. jhhdk: Forest, Tinder Wall, Young Wolf, Goblin Bombardment // 6-0, Leyline, Maze.
8. Tylert: Leyline of the void, Rishadan port, Mutavault, Chronomaton // 2-2, Port locks Karn out, Maze handles Chrono.
9. shiftyhomunculus: Tropical Island, Young Wolf, Daze, Nature's Claim // 6-0, I might lose Leyline, but Maze doesn't care.
10. RoosterCocoa: Subterranean Hangar, Phyrexian Obliterator, Faerie Macabre, Murderous Rider // 2-2, Edit: Forgot Rider can kill Planeswalkers. Agree on your drawing logic.
11. maxx!: Forest, Tinder Wall, Narnam Renegade, Collective Defiance // 2-2, I'll get Maze but I'll lose Karn.
12. mattamort: Leyline of the void, Unmask, Peat bog, Bitterblossom // 0-6, I can play Karn, but he can't do anything useful against a pile of Faeries.
13. Serguei: Peat Bog, BitterBlossom, Unmask, Surgical extraction // 0-6, Now I can't even play Karn.
15. silkster: Tinder Farm, Narnam Renegade, Goblin Bombardment, Leyline of Sanctity // 6-0, Leyline, Maze.
16. GoblinSmashmaster: Taiga, Tinder Wall, Collective Defiance, Crashing Footfalls // 0-6, Two creatures and no Karn.
17. FTW: Leyline of the Void, Badlands, Bloodhall Ooze, Duress // 2-2, Maze but no Karn.
58 points.