Kozilek, Butcher of Truth

When you cast this spell, draw four cards.
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents.)
When Kozilek, Butcher of Truth is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Magus of the Disk

Magus of the Disk enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Single Combat

Each player chooses a creature or planeswalker they control, then sacrifices the rest. Players can't cast creature or planeswalker spells until the end of your next turn.

Planar Collapse

At the beginning of your upkeep, if there are four or more creatures on the battlefield, sacrifice Planar Collapse and destroy all creatures. They can't be regenerated.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Sengir, the Dark Baron

Flying
Whenever another creature dies, put two +1/+1 counters on Sengir, the Dark Baron.
Whenever another player loses the game, you gain life equal to that player's life total as the turn began.
Partner (You can have two commanders if both have partner.)

Shadowy Backstreet

({T}: Add {W} or {B}.)
Shadowy Backstreet enters tapped.
When Shadowy Backstreet enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Boromir, Warden of the Tower

Vigilance
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
Sacrifice Boromir, Warden of the Tower: Creatures you control gain indestructible until end of turn. The Ring tempts you.

Wrath of God

Destroy all creatures. They can't be regenerated.

Day of Judgment

Volrath's Stronghold

{T}: Add {C}.
{1}{B}, {T}: Put target creature card from your graveyard on top of your library.

Yes Man, Personal Securitron

{T}: Target opponent gains control of Yes Man, Personal Securitron. When they do, you draw two cards and put a quest counter on Yes Man. Activate only during your turn.
Wild Card — When Yes Man leaves the battlefield, its owner creates a tapped 1/1 white Soldier creature token for each quest counter on it.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Merciless Eviction

Choose one —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all planeswalkers.

Kaya's Wrath

Destroy all creatures. You gain life equal to the number of creatures you controlled that were destroyed this way.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Promise of Loyalty

Each player puts a vow counter on a creature they control and sacrifices the rest. Each of those creatures can't attack you or planeswalkers you control for as long as it has a vow counter on it.

Akroma, Vision of Ixidor

Flying, first strike, vigilance, trample
At the beginning of each combat, until end of turn, each other creature you control gets +1/+1 if it has flying, +1/+1 if it has first strike, and so on for double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, protection, reach, trample, vigilance, and partner.
Partner

End Hostilities

Destroy all creatures and all permanents attached to creatures.

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Ravos, Soultender

Flying
Other creatures you control get +1/+1.
At the beginning of your upkeep, you may return target creature card from your graveyard to your hand.
Partner (You can have two commanders if both have partner.)

Terminus

Put all creatures on the bottom of their owners' libraries.
Miracle {W} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Damnation

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.