Ob Nixilis of the Black Oath costs {3}{B}{B} and is a Legendary Planeswalker that can be your commander. Its +2 makes each opponent lose 1 life and you gain that much, its -2 creates a 5/5 black Demon creature token with flying and you lose 2 life, and its -8 gets an emblem that sacrifices a creature to gain life and draw cards. A steady flow of 5/5 Demons is the plan.
The precon already has the best Demons and sweepers, including Reaper from the Abyss, Bloodgift Demon, Overseer of the Damned, Demon of Wailing Agonies, Magus of the Coffers and Mutilate. Each swap below pairs a cut with an add, and every card is scored with the same numbers the Oracle uses to build decks: synergy and inclusion from the Ob Nixilis decks, plus lift, which shows how much more often a card turns up in Ob Nixilis decks than in decks that could play it.
Looking for the unmodified list first? Read the Sworn to Darkness precon guide.
What is holding the deck back
Not enough Demons and Ob Nixilis planeswalkers
Ob Nixilis Reignited, Rune-Scarred Demon, Desecration Demon, Indulgent Tormentor and Harvester of Souls are Demons or Ob Nixilis planeswalkers. They are among the top-scoring cards the precon leaves out.
Shades, filler and removal outside the lists
Evernight Shade, Morkrut Banshee, Nekrataal and Phyrexian Gargantua are not cards Ob Nixilis, and Swiftfoot Boots, Nantuko Shade, Annihilate, Aether Snap, Dregs of Sorrow, Flesh Carver, Skeletal Scrying and Unstable Obelisk score low decks usually play.
Few payoffs for Demon attacks
Demonic Covenant draws a card whenever Demons attack and makes a 5/5 flying Demon every turn.
The 12 swaps
Each pair shows the numbers for the card coming out and the card going in. Click a card image to zoom.

Evernight Shade is a four-mana 1/1 Shade with undying. It is not a card Ob Nixilis decks usually play.
Ob Nixilis Reignited is a {3}{B}{B} planeswalker. Its +1 draws a card and loses 1 life, its -3 destroys target creature, and its -8 gives an opponent an emblem that makes them lose 2 life whenever a player draws a card. A five-mana planeswalker that draws or removes a creature, and the highest-scoring card the precon leaves out.

Morkrut Banshee is a five-mana 4/4 with morbid. It is not a card Ob Nixilis decks usually play.
Rune-Scarred Demon is a 6/6 Demon for {5}{B}{B} with flying. When it enters you search your library for any card and put it into your hand. A seven-drop Demon that tutors for your best card.

Nekrataal is a four-mana 2/1 first striker that destroys a nonartifact, nonblack creature. It is not a card Ob Nixilis decks usually play.
Desecration Demon is a 6/6 Demon for {2}{B}{B} with flying. At the beginning of each combat, any opponent may sacrifice a creature of their choice, and if one does, it taps and gets a +1/+1 counter. A four-drop 6/6 flyer that eats a creature or threatens a huge attack.

Phyrexian Gargantua is a six-mana 4/4 that draws two cards and loses 2 life. It is not a card Ob Nixilis decks usually play.
Indulgent Tormentor is a 5/3 Demon for {3}{B}{B} with flying. At the beginning of your upkeep you draw a card unless target opponent sacrifices a creature of their choice or pays 3 life. A five-drop Demon that draws a card or costs an opponent a creature or 3 life.

Nantuko Shade is a two-mana 2/1 Shade that pumps for {B}. It scores 7 in the data.
Exsanguinate costs {X}{B}{B}. Each opponent loses X life, and you gain life equal to the life lost this way. A scalable finisher that works with Ob Nixilis's life gain.

Annihilate is a five-mana instant that destroys a nonblack creature and draws a card. It scores 7 in the data.
Demonic Covenant is a Kindred Enchantment — Demon for {4}{B}{B}. Whenever one or more Demons you control attack a player, you draw a card and lose 1 life, and at the beginning of your end step you create a 5/5 black Demon creature token with flying, then mill two cards. If two cards that share all their card types were milled this way, you sacrifice this enchantment. A six-mana enchantment that makes a Demon every turn.

Aether Snap is a five-mana sorcery that removes all counters and exiles all tokens. It scores 10 in the data.
Abhorrent Overlord is a 6/6 Demon for {5}{B}{B} with flying. When it enters you create a number of 1/1 Harpy tokens with flying equal to your devotion to black, and at the beginning of your upkeep you sacrifice a creature. A seven-drop Demon that makes lots of flyers, and the Harpies feed its upkeep.

Dregs of Sorrow is a sorcery that destroys X nonblack creatures and draws X cards. It scores 10 in the data.
Harvester of Souls is a 5/5 Demon for {4}{B}{B} with deathtouch. Whenever another nontoken creature dies, you may draw a card. A six-drop Demon that draws a card from every death.

Flesh Carver is a three-mana 2/2 with intimidate and a sacrifice ability. It scores 10 in the data.
Kothophed, Soul Hoarder is a 6/6 Legendary Demon for {4}{B}{B} with flying. Whenever a permanent owned by another player is put into a graveyard from the battlefield, you draw a card and lose 1 life. A six-drop Demon that draws from every opposing loss.

Skeletal Scrying is an instant that exiles X cards from your graveyard to draw X cards. It scores 10 in the data.
Consuming Corruption costs {B}{B}. It deals X damage to target creature or planeswalker and you gain X life, where X is the number of Swamps you control. A two-mana instant that is removal and life gain in a deck full of Swamps.

Unstable Obelisk is a three-mana rock that can later destroy a permanent for {7}. It scores 11 in the data.
Ob Nixilis, the Hate-Twisted is a {3}{B}{B} planeswalker. Whenever an opponent draws a card, it deals 1 damage to that player, and its -2 destroys target creature and its controller draws two cards. A five-mana planeswalker that pings every draw and kills a creature.

Swiftfoot Boots is a two-mana Equipment that gives hexproof and haste. It scores 6 in the data.
Reiver Demon is a 6/6 Demon for {4}{B}{B}{B}{B} with flying. When it enters, if you cast it from your hand, it destroys all nonartifact, nonblack creatures. An eight-drop Demon that wipes every nonblack creature.
The full swap list
Cut
- Evernight Shade
- Morkrut Banshee
- Nekrataal
- Phyrexian Gargantua
- Nantuko Shade
- Annihilate
- Aether Snap
- Dregs of Sorrow
- Flesh Carver
- Skeletal Scrying
- Unstable Obelisk
- Swiftfoot Boots
Add
- Ob Nixilis Reignited
- Rune-Scarred Demon
- Desecration Demon
- Indulgent Tormentor
- Exsanguinate
- Demonic Covenant
- Abhorrent Overlord
- Harvester of Souls
- Kothophed, Soul Hoarder
- Consuming Corruption
- Ob Nixilis, the Hate-Twisted
- Reiver Demon
What to keep
These cards are doing the deck's heavy lifting. Do not cut them.
- Reaper from the Abyss$0.49
Played in 54% of Ob Nixilis decks. Destroys a non-Demon creature at each end step after a creature died. - Bloodgift Demon$0.42
Played in 53% of Ob Nixilis decks. Draws a card every upkeep. - Overseer of the Damned$0.23
Played in 45% of Ob Nixilis decks. Destroys a creature and makes Zombies from opposing deaths. - Demon of Wailing Agonies$1.72
Played in 39% of Ob Nixilis decks. Gets +2/+2 and makes opponents sacrifice a creature while Ob Nixilis is your commander. - Magus of the Coffers$4.79
Played in 42% of Ob Nixilis decks. Taps for {B} for each Swamp you control.
If you want to spend more
These are strong but sit outside a budget upgrade. Prices are the cheapest paper printing.
- Archfiend of Depravity$0.32
A five-mana flying Demon that makes each opponent keep only two creatures at their end step. It costs more than a budget upgrade should. - Ob Nixilis, Unshackled$4.05
A six-mana flying, trample Demon that punishes library searches and grows from deaths. It costs more than a budget upgrade should.
Sworn to Darkness already has the best Demons, the sweepers and Ob Nixilis's Demon tokens. The upgrade is cheap Demons and Ob Nixilis planeswalkers, in place of shades and filler that Ob Nixilis decks leave out. These twelve swaps cost about $5 in total.
Want a full 100-card list built around Ob Nixilis of the Black Oath from today's data?
Build with The Oracle →Frequently asked questions
What are the best upgrades for the Sworn to Darkness precon?
Using data from 710 Ob Nixilis of the Black Oath decks, the highest-scoring additions are Ob Nixilis Reignited (for Evernight Shade), Rune-Scarred Demon (for Morkrut Banshee) and Indulgent Tormentor (for Phyrexian Gargantua). The full list has 12 swaps, each scored with synergy, inclusion and lift.
How much does it cost to upgrade Sworn to Darkness?
All 12 swaps cost about $5.32 at the cheapest paper printings (TCGplayer market prices via Scryfall, 2026-10-28). If you want to spend more, the guide also covers Archfiend of Depravity ($0.32) and Ob Nixilis, Unshackled ($4.05).
What should I cut from Sworn to Darkness?
The weakest cards for this commander are Evernight Shade, Morkrut Banshee and Nekrataal. The guide explains the reason for every cut, and swaps each one for a card that scores higher.
Which cards should I keep in Sworn to Darkness?
Keep Reaper from the Abyss, Bloodgift Demon, Overseer of the Damned, Demon of Wailing Agonies and Magus of the Coffers. These are the cards doing the deck's heavy lifting.
What does Ob Nixilis of the Black Oath do?
Ob Nixilis of the Black Oath costs {3}{B}{B} and is a Legendary Planeswalker that can be your commander. Its +2 makes each opponent lose 1 life and you gain that much, its -2 creates a 5/5 black Demon creature token with flying and you lose 2 life, and its -8 gets an emblem that sacrifices a creature to gain life and draw cards. A steady flow of 5/5 Demons is the plan.
More Commander 2014 upgrade guides
How the numbers work
Inclusion is the share of Ob Nixilis of the Black Oath decks (710 of them when this was written, 2026-10-28) that play the card. Synergy is how much more often they play it than other decks in the same colours. Oracle score is synergy × 0.6 plus inclusion × 0.4, the same blend The Oracle uses to rank cards for a deck. Lift compares how often the card appears in these decks with how often it could, capped at 8× here; it is shown for context and does not change the score.
Two cautions. Players who run the precon unmodified count as Ob Nixilis of the Black Oath decks, which flatters every card the precon contains. Lift is high for many Demon cards because few decks play them outside a Demons deck, so use lift to compare cards, not to judge one in isolation. A card the commander's decks do not usually play counts as 0 in the average score. Prices are the cheapest non-foil paper printing on TCGplayer (via Scryfall), in USD, and move daily.











