This deck has been retired.
The deck has a heavy sacrifice theme. Literally 83 cards in the deck have the word "sacrifice" somewhere in the card including all the lands. Only the basic lands (12 of them) and seven non-land cards don't have sacrifice as some part of their ability.
Given this you will get additional advantages off playing any of the cards in the deck with Korvold, Fae-Cursed King draw and +1/+1 counters.
There is a lot of token generators in the deck, whether that be creatures or even other things like Treasures or Clues.
Eldrazi Spawn / Eldrazi Scions
There are some enchantment cards that generate scion tokens; Awakening Zone, From Beyond.
These are perfect as you can sacrifice them for mana while also drawing cards and even potentially setup Korvold for huge power and toughness boost threatening lethal commander damage.
Treasures
There are a number of ways to produce treasure tokens, which are perfect as they provide additional mana and draw with Korvold.
These are Dockside Extortionist, Ruthless Knave, Pitiless Plunderer, Brass's Bounty.
Ruthless Knave can be used to sacrifice token creatures to produce treason tokens. With Korvold in play you'll get to draw 3 cards if you sacrifice the treasures for mana all up for each you spend, as it cost 3 mana but you get 2 from the treasures.
There is a lot of land ramp in the deck, so getting a sizable number of lands to make Brass's Bounty produce lots of tokens is easily done. It can be a game winning play as you get to draw a card each time you sacrifice one of the treasures.
Dockside Extortionist is also an easy way to produce tons of treasures. As the game goes longer it's effectiveness to produce lots of tokens goes up. An excellent card as it scales with opponents success.
Pitiless Plunderer represents a massive amount of potential card draw, as it get's triggered by token creatures as well. Sacrificing Eldrazi tokens for example will generate treasures and these in turn can be sacrificed for more mana and draw.
Clues
There is a smaller element of getting clues which are also great with Kovold's abilities.
Tireless Tracker in conjunction with the land ramp can produce a solid amount of clues each turn. With Kovold you can sacrifice them to draw 2 cards, which is worth the mana investment at times.
There are a myriad of ways to produce creature tokens in the deck, representing ways to produce permanents for sacrificing.
These include Endrek Sahr, Master Breeder, Tendershoot Dryad, Avenger of Zendikar, Turntimber Sower, Prossh, Skyraider of Kher, Nesting Dragon, Titania, Protector of Argoth.
Because there are a lot of ways to generate token creatures, we have some special ways of sacrificing these for advantages.
Yawgmoth, Thran Physician for additional draw and creature removal.
Viscera Seer is cheap to cast and gives you scry on each sacrifice.
Phyrexian Altar and Ashnod's Altar are powerful tools for generating mana.
Now there are some cards that produce tokens that have their own inbuilt sacrifice outlets as well.
Turntimber Sower and Prossh, Skyraider of Kher.
Phyrexian Tower allows you to sacrifice a creature.
The land ramp or searches also have sacrifice effects, which allow for card replacement, as well as additional lands. Because the land ramp is all based around basic lands, the only non-basic lands are fetch lands and utility lands that allow advantages through sacrificing.
Literally 23 lands in the deck have sacrifice as part of the card, so you can draw a card for 2/3 of your land base. This makes it super easy to get card advantages with Korvold simply based off your lands.
There are some cards that allow you to search for any land, and not just basics, Elvish Reclaimer, Crop Rotation, Scapeshift.
There are a number of utility lands in the deck, so you can use these to get something that will help at that stage of the game.
Scapeshift can be a game changer with the massive draw you can get off sacrificing lands. You can setup for more draw by searching for lots more fetch-lands. Try and setup getting value off Field of the Dead as well.
For example say you cast Scapeshift with seven lands in play. You could go for something like Bloodstained Mire, Marsh Flats, Misty Rainforest, Prismatic Vista, Verdant Catacombs, Wooded Foothills, Field of the Dead.
This will draw you 7 cards in the first place with Korvold.
Field of the Dead will trigger 7 times as well getting you Zombie tokens.
The on your next turn you can sacrifice your search lands and get a mix between Snow-Covered and normal basics so that Field of the Dead will still get triggered with "different names". That will mean drawing 6 more cards and getting 6 more Zombie tokens.
The removal in the deck has the clever design of also sacrificing (as part of the effect) allowing you to replace the cards you use against opponents.
These are a mix between artifact and enchantment removal, Caustic Caterpillar, Viridian Zealot, Thrashing Brontodon, Ingot Chewer, Seal of Primordium.
There is also creature removal with Shriekmaw and Executioner's Capsule.
Grave Pact and Dictate of Erebos with all the creature tokens and sacrifice outlets will mean you can easily remove your opponents boards of creatures, on-going as well.
Remember we have Yawgmoth, Thran Physician that can be used for killing off opposing creatures with so much creature token generating in the deck.
Mayhem Devil is similar in that you can deal damage to creatures with every sacrifice you do, controlling the board potentially of a troublesome creature. But it can also target planeswalkers and opponents giving you further reach on troublesome targets.
There are a few artifacts that can be sacrificed for value, meaning you'll get the draw and pump with Korvold.
Nihil Spellbomb can draw you 2 cards when used, so effective to hedge against graveyard strategies. Also you can sacrifice it to Korvold as part of his coming into play or attacking clause and even though you won't exile graveyards you can still spend to get an additional draw.
Wayfarer's Bauble can get lands and draw.
Because you get draw from almost every card in your deck with Korvold on the battlefield you will often be discarding cards due to hand size at end of turn. The deck has lots of ways of producing mana, but it's not a storm deck that looks to play out your cards in single big turns. It's more like you get to filter for cards that will serve you best at that stage of the game.
However we can use setting up our graveyard for a number of cards, so think of end of turn discarding as a setup for the future, and not as a loss of potential resources.
World Shaper and Splendid Reclamation allows bringing back lands that are in your graveyard. Combine this with the fact that we have lots of sacrifice land effects, like fetch-lands and spells which sacrifice lands in play to get others from library.
Major combos to look for are using land sacrifice outlets in conjunction with these to get maximum value; Sylvan Safekeeper, Need for Speed, Squandered Resources.
You can even look to sacrifice all your lands in the attempt to draw into one of the graveyard recursion cards if you are in a tight corner (I have done this many times).
Sylvan Safekeeper can also be used to sacrifice lands for the protection. Saving Korvold from spot removal is going to be worth it most times.
Need for Speed and Squandered Resources can be used to sacrifice lands in order to draw into much needed cards.
Living Death can be used in several different ways. It actually makes you sacrifice your creatures in play so this can be used for draw and getting the creatures back from your graveyard. A lot of the creatures have self-sacrifice abilities for advantages, so chances are you've got a graveyard filled with creatures.
But you also have a high chance of having a way to sacrifice all your creatures in play anyway, so you can send them to graveyard before it resolves and then you get the creatures back straight away anyway.
Another good thing about this deck is that you don't actually need Korvold in play for the deck to still have a proactive game. He literally just represents additional value to the cards that you are already playing, albeit much more busted.
The +1/+1 counters can be both and blessing and a curse, which sums up Korvold existence nicely. He can represent an enormous creature quite quickly via sacrificing permanents and can easily attack for commander lethal (or just lethal damage) on opponents. But this in turn can make him a target for removal.
But it is nice to have a huge flying creature to eliminate the next most threatening player and also use him as a political way to leave your stuff alone. "If you attack me then I will attack you with Korvold", type stuff.