Just came here from your help posting.

First, on the mana rocks and lands. You could probably count Sol Ring as a land, however most of your others are a little too expensive. I'm also not sure if City of Traitors actually counts as a land (it's more like a ritual?) It may be useful to separate these into custom categories (mana, card draw, removal, etc..).

As for cutting cards, I'm gonna guess they should mostly come out of the big column of artifacts, and generally some of the more expensive ones. You have 10 6 mana artifacts! That sounds like a ton to me. Does Mycosynth Lattice actually do anything good for you? Same with Liquimetal Coating (opponent having artifacts makes All Is Dust worse). What does Ashnod's Altar do?

You have a couple themes that I'm not sure are fully supported. How many artifacts with cool tap effects do you have? Do those justify Clock of Omens/Unwinding Clock? Does Magistrate's Scepter have enough charge counter support?

Putting into custom categories can also help you see if you have enough card draw etc.. (or too much/which cards are the worst in their respective categories)

hubatish, Mycosynth Lattice and Liquimetal Coating allow karn to blow up lands of the opponents, also they don't make All Is Dust worse as they would still have the colour identity regardless of whether or not they're artifacts.

hubatish, Mycosynth Lattice and Liquimetal Coating also allow me to steal stuff via Staff of Domination City of Traitors is good for early burst or keeping till late game and dropping it after I'm out of lands to play. It can also come back via Crucible of Worlds.

Mycosynth Lattice + Darksteel Forge = my lands are indestructable tooMycosynth Lattice + Buried Ruin = I can yank any card I want, i.e. City of Traitors, back from my graveyard. Clock of Omens/Unwinding Clock Mean I can swing all out with large artifacts then untap them with small ones, allows me to untap and put extra counters on Magistrate's Scepter, and also can combine with things like Mycosynth Lattice and a few other cards on here and buy me infinite mana.

See the Karn interactions section of this deck for more: Walking Fridges And Stuff. I took a lot of ideas from here and shopped around to other decks for inspiration.The 6-mana cost artifacts are in there to be beat sticks as well as give me their abilities. I look at 6cmc cards as 6/6 creatures, 5cmc as 5/5 creatures, ect on top of what they are.

THAT being said, I have thought about cutting City of Traitors, as this deck has enough land. As well as Maze of Ith and Eye of Ugin, as they don't give me mana. That's another reason land's at 38 right now, because 2 of them don't give me mana.

Ashnod's Altar can allow me to sac artifacts for mana just to get them back later with other cards, however I've been considering cutting it too. It can combo with other cards, i.e. token producers + Mycosynth Lattice, or accel me into something big.

I do love getting this feedback tho, feel free and please do make a counterargument, because that's really going to help me make the hard choices here.

No problem Burgdawg, thanks for coming back. For Lattice/Cooling though, I fail to see how Staff of Domination allows you to steal artifacts? Or really any card in your deck that says "destroy target artifact" or do something bad to an opponent's artifact (like steal it).

For Ashnod's Altar - yes it can combo with token producers but uh.. you have no token producers in this list? (Mirrorworks maybe?) It's time to focus on your deck, not the abstract potential of these cards. If you toss another 4 land in there (putting it at 116 cards) you could also just start playtesting and see what you want to cut that way.

Crap, idk where I was pulling that stealing thing from, must have been the drugs. They do allow you to play all their stuff with Ornate Kanzashi, but I must have cut him at some point.

As for Token producers, I have: Mirrorworks Trading Post Springjack Pasture Mimic Vat and Prototype Portal.

And thanks for the piece of advice of separating them into custom categories, Really helps me see a better layout of the deck!

Ok hubatish, I think I got the categories better now. So much mana o.O

It is a lot. Good luck figuring out what to cut! +1 for lots of sweet cards and explaining some synergies

<3 Bless you kind sir.

"I have been summoned"

the list looks very good +1 but i can only take a quick look at it right now so forgive me if i missed something. i like that you went both ways, too. playing only beatdown or combo makes the deck a bit easy to interrupt.

you don't really need 38 lands. most of the time im running like 32-34 (32 + Dark Depths and Maze of Ith at the moment) and thats totally fine.you only need a few to get rolling the rest is about your rocks. hell if you get workshop or ruins into play you (almost) dont need any other lands. thats why so many ppl play stasis with karn. Winter Orb with a Scorched Ruins and 1-2 rocks in play, yes please. but ofc playing winter orb is a sin in many playgroups.

try to pick up a Mana Crypt if you get a chance. that allows a turn 1 win every now and then. makes you giggle and no1 is mad because it was that fast ;)

the avg. cmc in a good karn deck can be way higher than other decks' average because it supports the beatdown plan. by 'good' i mean playing every accelerator land and rock; so everything that gives more mana than it costs

oh and in other news... it seems like barries land will finally get released. that means we will have access to a colorless basic land which opens up many new ways to build a karn manabase. it also makes cards like Solemn Simulacrum good for karn and Path to Exile less scary. fingerscrossed

ps: i envy you...awww The Tabernacle at Pendrell Vale /want

PepsiAddicted YES thank you for coming, so nice to have input from someone who seems to run this guy a lot. He's a pretty niche commander and hard to wrap your head around. I am trying to pick the best of both worlds when it comes to the beatdown/combo mix. I hate cutting down decks to their exact size, so many good things. :( I'm at 104 so... close... Any suggestions are helpful, I put Mana Crypt back in.

Yes, I love Winter Orb. My favorite deck of mine is my Grand Arbi/tax/prison deck. I had it in and cut it earlier due to the average cmc of the deck, but you're right, with lots of rocks, tap/untap effects, and lands that tap for 2 it's worth it.

PS: I'm curious as to how your 1st turn wins went with Mana Crypt. Infinite combo I'm assuming?

example turn1 win hand

i find it rather hard to tell ppl what to cut. as mentioned before ashnods altar is great but maybe not the very best card in here. ironworks maybe instead. and if you want a sac option to kill karn in case of stealing effects there are better options in utility lands. but i dont really know how often you do the whole token thing so maybe thats a really important part of your deck list... in that case dont listen to me ;)

Edit: nvm, suggested a card you already have listed.

PepsiAddicted I'm actually going to yank out The Tabernacle at Pendrell Vale. It is only useful in certain situations, such as with Winter Orb or with token decks, and this deck has other ways of dealing with that. If it makes you feel any better, I never actually owned the card, I make deck lists on here the best I can cost notwithstanding, then test them on X-mage, then if I really really like them and actually have a format to play them in, do I actually buy the cards. I swapped Ashnod's Altar for Krark-Clan Ironworks, it's one more but more useful. Staff of Domination was a hard cut too but it's too expensive for what it does in this deck. Most of what it did was unnecessary or done better by other cards.

ive been trying to find a tabernacle for quite some time now. Its true that it is not really necessary but its an awesome card ;)

Staff of domination is only worth it if you are aiming for another infinite combo wincon