Where in the deck would you make room for Sylvan Library, Grave Pact, and Damnation? I'd probably remove the Chupacabra for Pact, suggestions?

I would cut the Slum Reaper before the dog. He's Maz's best friend after all, plus the reaper has redundant copies in the 3 drop slot. I think Pox under performs unless it's played after Mazirek, so that could be an ok cut. For the last card I'm stuck between Dark Prophecy, Reprocess, and Ruthless Knave. None of those cards are really bad, so cutting one is hard for me to figure out. All three of those cards have helped me win games but have also helped me lose in different games. Personal preference and your metagame will determine this choice I think. I'm curious how it all works for you. Come back and post a message after you've played with it and let me know what you chose. Cheers.

I'm a little newer to the format, so some card choices can be confusing to me sometimes.

Instead of Sylvan Safekeeper, would it be easier to just run Lightning Greaves? I get sacrificing stuff is our jam, just seems like sacrificing lands is a pretty high cost of business? Am I missing some synergy somewhere?

It lets you sacrifice lands to pump your team with Mazirek out so you can win in one attack. There isn't really a downside because the game ends that turn anyway. Also in the early game it's easy to just sacrifice him for value. It's great the way you don't have to equip it to one creature and it can work for all your creatures at once instead. And people don't really waste removal spells if they know you can counter it by just sacrificing a land. Even though haste is cool the overrun pump effect that the commander provides already works the moment that its in play. So yeah there's a few reasons.

One more question (sorry haha), what's up with the Emissary? Is Manifesting just another "cool stuff when it dies" effect you have? Just curious!

Thanks for the answers.

A manifest is better than a token, many effects in the deck only trigger from the death of a non-token. Its just another piece of sacrificial fodder. Slightly better them Doomed Dissenter.

Couple more things. Sorry to horde so much of your decklist's comments... :/

I got my hands on a Doubling Season. Is it worth it to run two of the effects? Should I keep Primal Vigor in? The deck isn't together yet, just trying to get an idea from your own experiences.

Volrath's Stronghold. How important is it? I'll probably find one in the future but for now I don't have access.

Swarmyard is protection for the commander. Should I run it alongside the Safekeeper, or instead?

Thanks for everything!

If I had a Doubling Season, I would totally run it alongside Primal Vigor. Seems fun.

Volrath's Stronghold is great, but I happened to own it already. Not sure if its all that necessary, but its good in the deck.

Swarmyard is a good looking protection effect since Mazirek is public enemy #1, but I've never used it personally. I guess Yavimaya Hollow is better anyways.

Link your version here once you assemble it I'm curious to see how it ends up.

Earthcraft plus some more emphasis on basic lands so that all your creatures, including the token creatures, tap for mana without needing haste to grind out more value? Makes Eldrazi Scions and Spawn make 2 mana? Also, what are your Protean Hulk lines usually when someone runs hulk (generally with Flash) they have a specifc few creatures they run to win? Speaking of winning, how do you win? Combat?

After viewing the cards from new Golgari guild, it seems like Mazirek now has a wife - Izoni, Thousand-Eyed. What do you think about it?

Oh yeah, Izoni's already been preordered for a while :) I'm super excited for Guilds of Ravnica, a few cards from it will definitely make their way in. Once the cards are in my hand physically I'll update the list but I also bought a Midnight Reaper already. Vraska, Golgari Queen is perfect too but the preorders were over priced so I'm gonna wait on buying her.

Plaguecrafter seems like a perfect fit as well, if it has not caught your eye. Also, you may have mentioned it, but why is Titania, Protector of Argoth not part of the deck?

Totally, Plaguecrafter is another one I preordered for this deck the other day...I really like effects like that. So much that I already paid for 4 copies to put into various commander decks.

Titania is a powerful token generator for sure. I don't have a copy currently. I decided to focus on less mana costed token makers, things more like Blisterpod. She has been on my radar to try out in here for a while however. In builds that have more fetch lands she is a little more impactful too. Some people push toward the land sacrificing angle more than I have, including cards like Squandered Resources or Scapeshift. Which are all cool ideas using cards that I don't own currently. I'll keep an eye out for a copy of Titania, it does seem like she would probably be great.

Thanks for all the great suggestions!

Why does persist crest an infinite loop? Do you have a way to remove the -1/-1 counter that I am missing?

If a +1/+1 counter and a -1/-1 counter is on the same creature at the same time they cancel each other out and are both removed as part of a state based effect. It's in the rules somewhere, I didn't make it up...but I don't remember exactly what rule number it is.

I never knew that. I feel like I need to make a deck to play with it. Sweet deck dude.

I'm super happy to see Vraska, Golgari Queen fit into another deck! She's so fun, and I've killed people multiple times using player deathtouch.

Have you considered Black Sun's Zenith before? A few counters on your creatures will prevent them from dying, and all of the death's resulting from having toughness reduced to 0 or less are additional sacrifice triggers.

Nice write-up! Probably took some good time to type it all down. I did have to sort your deck on type instead of your custom types to make some sence of it though ;) I’ve been working on a meren deck with a similar sacrifice idea for a couple of years now, though the plan is a bit different they here I do have some suggestions and tips based on my experience with the archetype.

There are probably some cards here that have been mentioned before or have been tested, so sorry for that.

sac outlets are the bread and butter of these types of deck. You always need one in play or the deck falls short (this is also one of the weak point that you can attack these decks on). Some sac outlets that I haven’t seen mentioned yet:

1) Evolutionary Leap . Except that it’s not a free sac outlet I think one of the best out there!
2) Spawning Pit . One of my favorites, create more tokens from sacing creatures and it’s free to activate. Also it can quite easily go infinite with Doubling Season
3) Attrition . It’s probably mentioned somewhere her and I probably looked over it because everyone knows this.
4) Altar of Dementia . Better in meren then it’s here but still has its uses if you want to go with an infinite combo.
5) Culling Dais . Value
6) Dark Privilege . Protection of commander and outlet in one.
7) Fallen Ideal . Recurring outlet is always nice.
8) Yahenni, Undying Partisan . Indestructible outlet.
9) Helm of Possession . If people are going big.
10) Plagued Rusalka . If people are going wide.
11) Claws of Gix . Can sac any permanent and is the cheapest outlet ever made.
Some utility creatures:
12) Wirewood Herald . This is one of my favorite fun cards in my deck. Your already playing a few good other elves (rec sage, izoni, wood elves, elvish visionary) so I definitely suggest adding this one!
13) Viridian Emissary and Primal Druid are all stars in my deck. Might be useful here over some of the 3 mana ramp creatures?? (Emissary is a bit better because of clamp, and it’s an elf).
14) Golgari Findbroker . Witness #2, also it’s an elf.
15) Sengir Autocrat and Mitotic Slime . These cards give 4 and 7 sacrifices respectively. They are some of the payoff cards that I use. Especially fond of autocrat since it works with savra and skullclamp very well.
16) Reassembling Skeleton . Another one of my payoff cards, and can get nuts of I have a good board. Also there are few ways to go infinite with this one (there is a 4 card combo with this in your deck right now).
17) Savra, Queen of the Golgari . It’s an elf and since it’s a creature its easier to tutor then an enchantment. The life gain is also nice!

And one more random card that doesn’t belong in above categories:
18) Foster . At 4 mana a bit expensive but boy what value this card can give!

Some of the cars you tested and took out I’d like to comment on. I find them very very useful and would probably never cut them in my deck:
19) Fecundity . This card is the best card in my deck, the only time it’s not great is when I’m playing against weenies or people are trading creatures with each other without me having a board presents. I don’t really care if people draw a card if I kill there 6 mana creatures because it still slows them down. What’s so good about this card that It provides us with a great amount of value. This card draws of tokens which is awesome and most of the creatures your running give to sac triggers anyway. In 90% the cases this card will generate more value for us then for other players.
20) Deathreap Ritual . The only reason I’d ever cut this card is the mana cost, which at 4 is a bit expensive. You however stated the reason for excluding this card is the lack of value. I’d like to point out that Morbid doesn’t only trigger at the end of your turn but at the end of EVERY turn. It also triggers when any creature dies, so it doesn’t have to be yours and, like fecundity, it triggers of tokens dying to!! In a four player game this card can give an easy 4 cards a round.
21) Golgari Germination . I like this mostly because I play above mentioned cards which benefit hugely from tokens dying, but even without this it’s a great card rewarding you for any sacrifice and being an enchantment it’s a bit more durable as well.
22) Sakura-Tribe Elder . At two mana and a build in sac outlet this card is a cheap ramp spell that functions at all time and can provide value even if you don’t have a sac outlet in play. But if you have experienced trough testing that you get more value out of a 3 drop ramp creature then it might be different for your deck compared to meren.

Hereby I end my epistle with a last note that if your looking to take out some card I’d look at everything above 4 mana and everything with X in the mana cost. I find I always take out these in the end since I can’t cast them reliably. (5 drops stay when they are very good for the deck though).

Thanks for the suggestions Spacebeest. You are right I've either actually tried or genuinely considered all them... except for Helm of Possession . And its a pretty fun sounding idea. I'll have to think about how to add it in. Thanks :)

Woodfall Primus, Aerie Ouphes, Animation Module are all infinite combos with Mazirek.

Add Bloodspore Thrinax to build a heavy threat and also as a back-up infinite combo creature for persist if mazirek is removed

In addition, you can get good use from Pitiless Plunderer as it allows you to get mana like phyrexian altar, but as an additional effect from any method you use to kill your creatures

Hey thanks for the suggestions!

However I'm not interested in focusing on making the deck combo off with infinite combos every game. Actually I find winning that way pretty unsatisfying and I generally avoid it with my play group. I do have a single persist creature in the deck, but it's more of an emergency backup than the primary plan.

The plunderer was ok in practice, but it was cut for a card that made creature tokens or drew cards I think.