Greater Gargadon is a card that the Command Zone podcast mentioned in their brawl-to-commander video for Korvold. I completely agree with their decision to toss the Gargadon into the deck. It provides a great sack outlet that can even get rid of our extra lands through sacrifice, which helps draw a ton of cards and make Korvold huge. Plus, once the time counters leave it, we get a huge threat that also can be sacked off.
Greven, Predator Captain gives us another sacrifice outlet that draws us a ton of cards, which helps pump up Korvold a bit more. Its only downside is that it makes us lose life, which means we have to be careful with how much we activate its ability.
Krav, the Unredeemed provides us with another sacrifice outlet than can sacrifice creatures en masse while also drawing tons of cards, gaining tons of life, and buffing both Krav and Korvold. Sounds like a great deal to me!
Plaguecrafter is a one-time sacrifice outlet that comes with the added bonus of making our opponents sacrifice one of their creatures. This allows us to play it, sack it to itself, buff Korvold and draw a card, and make our opponents go down a creature. It's a good card normally but it really shines in this deck.
Priest of Forgotten Gods is an absolute powerhouse in this deck. When we activate its ability, we sacrifice two creatures, draw 3 cards, add two black mana to our mana pool, put two counters on Korvold, make our opponents lose two life, and make our opponents sack a creature. Whew! That's a lot of damage!
Prossh, Skyraider of Kher gives us another threat in the air along with Korvold that comes down with tons of little tokens to sacrifice. It can sack creatures to both buff itself and Korvold along with drawing tons of cards, and it can act as the commander of the deck if you really want to brutalize your poor opponents. The reason I don't suggest it is because it's too powerful for a normal, fun game of EDH. Leave Prossh to cEDH.
Ruthless Knave is kind-of a hidden all star for this deck. You can pay 3 mana and sacrifice a creature to make 2 treasures, which can be sacrificed themselves to generate mana. That's an insane amount of value for our aristocrats-style deck. Remember, Korvold likes eating his friends but also his wedding gifts, and treasure seems like a decent gift!
Shattergang Brothers is another card that could function as a commander for the deck, but it's better in the main 99. It allows us to sacrifice a creature to make all of our opponents sacrifice a creature, and does the same with artifacts and enchantments. I love this tradeoff because our deck wants to be sacrificing stuff but our opponents don't want to. Plus, we get cards and counters for sacking our stuff. Me likey!
Sidisi, Undead Vizier is this deck's budget-ish version of Demonic Tutor. We get to sack a creature, draw a card, buff Korvold, and tutor for any card we want. This effect is something this deck really puts to great use, and if I drew Sidisi every game, I wouldn't have a problem with it.
Vaevictis Asmadi, the Dire is a very fun chaotic-style card that makes everyone have a good ol' laugh when it Chaos Warps a bunch of stuff, including our own stuff. The upside is that instead of shuffling it into our library, it gets sacrificed. That means we get Korvold triggers! This card is just all around fun and functions as some pretty decent removal.
Viscera Seer is a great turn 1 play in this deck. It allows a free and repeatable sacrifice ability to fix our draws for just one mana. In Korvold, this is especially great because we can scry to see what we'll draw off of Korvold.
Birthing Pod is an absolutely amazing card in this deck. It gives us the ability to sacrifice a creature to tutor up another creature with CMC 1 greater than the previous creature. This can lead to some pretty silly combos, like sacrificing a Bloodghast to fetch an Eternal Witness, and then playing a land to recur the Bloodghast. It is just an absolute powerhouse in this style of deck and it really brutalizes your opponents.
Culling Dais is a very underrated card for an aristocrats style deck. It can function as a pretty-much free sacrifice outlet once a turn, and then draws us a bunch of cards if we need it in a pinch.
Trading Post is a great card that enables its own combos. It allows us to sacrifice artifacts to draw cards, and then also sacrifice creatures to recur our artifacts. It's quite the fun combination that allows us to sacrifice a lot of things and recur them for value.
Witch's Oven is a great sacrifice outlet in this deck. It allows us to sacrifice our small creatures for a food token, and sacrifice bigger creatures to get two food tokens. This combos well with Gilded Goose because it gives it more food tokens to generate mana.
Goblin Bombardment isn't our greatest sacrifice outlet, but it's quite helpful in certain situations; sacrificing creatures to ping stuff can be surprisingly relevant! Other than that, it's just another way to sacrifice stuff to buff Korvold and draw cards.
Greater Good is quite a nice sacrifice outlet in certain situations. It's a free sacrifice outlet that allows us to draw a bunch of cards, with the downside of making us discard some cards every time we use it. This does kind of suck when we have to use it to sacrifice anything with power 1 or less, because we net lose cards. However, it's very helpful in sacrificing any other creatures. It works especially well with Greater Gargadon, because it can sacrifice the Gargadon to net draw 7 cards (including 1 from Korvold).
Vraska, Golgari Queen is a wonderful planeswalker that fits right into the deck. The +1 ability gives us a sacrifice while drawing us another card and gaining a bit of life. This is already enough to guarantee it a spot in the deck. But wait, there's more! It also blows up permanents and gives all of our creatures player deathtouch. Pretty solid!
Total Stats: This deck includes 23 nonland sacrifice outlets (including 5 mentioned in the ramp category; Gilded Goose, Springbloom Druid, Ashnod's Altar, Phyrexian Altar, and Harrow. This doesn't include permanents that sacrifice themselves. Of the sacrifice outlets, 13 are creature-based, 6 are artifact-based, 2 are enchantment-based, 1 is spell-based, and 1 comes in the form of a planeswalker. This number is very high, solely because we always want a sacrifice outlet, and it's great to have some versatility in our sacrifice outlets. Of the ones we've got here, my favorites are probably Sidisi, Undead Vizier, Birthing Pod, and Culling Dais.