So, for those of you who haven't been introduced, this is my new best friend, Marchesa:
There's a lot of cool keywords that work well with her, but of all of them, I think the most powerful might just be the sadly underused modular. You know, like arcbound ravager and....um....did I mention arcbound ravager?
OK, so the arcbound creatures outside of ravager are not very good, but they interact ABSURDLY well with Marchesa, and that absurdity can be used to fuel all sorts of other shenanigans. Besides that, other artifact creatures work stunningly well with marchesa and with arcbound creatures, like steel overseer and mindless automaton and triskelion. So, why not try an artifact build?
Basically the game plan is to get engines going early with arcbounds and sac outlets to generate lots of counters and recursion. This could fuel draw (strix, mindless automaton, scarecrone, kelpie, clamp, prophecy), removal (grave pact/dictate, duplicant), tutor (forgemaster), mana (altars) discard (hypnotist) etc. There's a decent amount of control to mess with other peoples' game plans while the board is being set up. Once you've got a pleasant amount of sac triggers going off, you can turn them into hot fiery death by either using them for a ton of damage (purp, flayer, surge, shadows), infinite turns with time sieve, or just jokulhaups and overrun with derpy little artifact dudes.
Sadly I don't yet have a workshop, but I'd like to get one for this deck.
You may like to consider Novijen Sages and Sage of Fables as additional sources of card draw that work with +1/+1 counters. Sage of Fables would also put a counter on your commander when she enters play, which is a pretty handy way of ensuring she recurs herself.
Unspeakable Symbol is decent as a way to ensure the Dethrone ability activates if you find yourself taking a lead in life totals (and you want to get free +1/+1 counters on attack).
Sage of Hours may be interesting too, although it would probably still be too hard to reliably get extra turns with him he may as well be a Flagbearer given how people evaluate him as a threat (Unspeakable Symbol and Sage of Hours kind of combo if you're desperate for an additional turn).
novijen sages looks too expensive for me. At 6 I'm trying to play game-enders.
sage of fables is better, although it really only gives counters to my general, that is a weakness of the deck. Currently the only reliable way to put counters on marchesa is with her own ability.
unspeakable symbol is ok, fits the same role as sage of fables but with more flexibility at the expense of the draw ability. Lowering my life total isn't my goal, I rarely plan to attack, most of my endgames should kill the table in a few turns and don't require attacking.
sage of hours would be nearly impossible for me to use. No.
I do want some good ways to put counters on marchesa, but I also don't want so many that it becomes better to use more non-artifact creatures with etb abilities, and then the whole strategy of my deck changes. So I might just rely on combat and opal palace, and see how it goes. Oh, and extruder. God I love extruder.
Extruder is a great card that combines a sacrifice outlet with a source of +1/+1 counters. Edit: Oops, missed that you had this already.
I would definitely not underestimate Unspeakable Symbol. It lets you save any creature that is about to die (and doesn't already have a +1/+1 counter), including your general, for no mana and the measly cost of 3 life. The ability to arbitrarily lower your own life to turn on Dethrone is pretty neat too.
Yeah, I think I'll need to include unspeakable symbol, it's just a little too good not to use. I'll probably cut sad bot, since i've only got 2 basics. Sort of a mistake on my part to include it, really.
Equipment doesn't work well enough, I don't think, since it will be unequipped after sacking, and the equip is a sorcery speed ability. power conduit I like a lot more, I'll have to see how often I feel like I've got extra +1/+1 counters though. At least it's an artifact. That reminds me, I really need to run skeleton shard in this deck.
I don't need duplicates for jokulhaups, 1 is plenty with the tutors I have.
the disk lockdown combo seems way too slow for this deck, I'll leave that for dagsson decks. darksteel forge itself is pretty decent for the deck, and I could see running it along with dagsson, but I want a low curve so I think I'll pass.
I really like the artifact focused build, though I think that a few cards are a bit suspect. Stifle is particularly out of place in a multiplayer setting, as there are only a handful of abilities that you're likely to ever counter, making it a dead draw most of the time. If you really need all the control in the world I'd think that Pact of Negation would pull much heavier duty. Also, the deck ends up over max hand size all the time, so I'd say that Reliquary Tower is a must - I'd switch out a basic or maybe the Cavern of Souls. Also, I understand that the modular version of this deck does particularly well with sac outlets, but some of them seem just kind of meh - I'd probably replace some of them with the ravinica signets and/or mirrodin talismans, particularly Viscera Seer and Goblin Welder.
Edit: Also, I feel like Phyrexian Metamorph desperately wants to be part of this deck, though I'm not certain what to cut.
Really am enjoying this deck build. I think you have too many low power artifacts which fit the theme, but are too redundant. Mikeaus, the Unhallowed seems like it should be in here as its a near instant win as would be geralf's messenger. Is there a way to abuse evoke with this build?
Mikaeus, the Unhallowed doesn't play well with all the Modular shenanigans, which I assume is the reason he is not in here. Geralf's Messenger is also a pretty slow way to kill the table, even if you do get the sacrifice every end step.
Goblin Welder is one of the best reasons to be in the colour red if you're playing with an artifact theme, it is certainly not 'meh'.
I love welder, but with no haste sources, a surprisingly low number of high-impact artifacts, and a bunch of other repeatable ways to recover artifacts I think he's much more situational than would normally be expected. That said, looking over this some more he's still probably superior to Junk Diver (lack of a 'may' option on diver and Myr Retriever severely hurts both cards, though retriever may be cheap enough to be playable).
I really love this list! How did it play so far?
I wanted to recommend Shimmer Myr, but you already run that.
I would probably cut some of the one-shot controll cards, but you'll probably have a reason for that