Ancestral Mask

Enchant creature
Enchanted creature gets +2/+2 for each other enchantment on the battlefield.

Getting

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Fight Rigging

Hideaway 5 (When this enchantment enters, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.)
At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if you control a creature with power 7 or greater, you may play the exiled card without paying its mana cost.

Darigaaz's Caldera

When this land enters, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {B}, {R}, or {G}.

Haunted Cloak

Equipped creature has vigilance, trample, and haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

Sol Ring

Infiltration Lens

Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}

Kediss, Emberclaw Familiar

Whenever a commander you control deals combat damage to an opponent, it deals that much damage to each other opponent.
Partner (You can have two commanders if both have partner.)

Bard Class

(Gain the next level as a sorcery to add its ability.)
Legendary creatures you control enter with an additional +1/+1 counter on them.
{R}{G}: Level 2
Legendary spells you cast cost {R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
{3}{R}{G}: Level 3
Whenever you cast a legendary spell, exile the top two cards of your library. You may play them this turn.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Rakdos Carnarium

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Legolas's Quick Reflexes

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Untap target creature. Until end of turn, it gains hexproof, reach, and "Whenever this creature becomes tapped, it deals damage equal to its power to up to one target creature."

Chevill, Bane of Monsters

Deathtouch
At the beginning of your upkeep, if your opponents control no permanents with bounty counters on them, put a bounty counter on target creature or planeswalker an opponent controls.
Whenever a permanent an opponent controls with a bounty counter on it dies, you gain 3 life and draw a card.

Gruul Signet

Awaken the Ancient

Enchant Mountain
Enchanted Mountain is a 7/7 red Giant creature with haste. It's still a land.

Excalibur, Sword of Eden

This spell costs {X} less to cast, where X is the total mana value of historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)
Equipped creature gets +10/+0 and has vigilance.
Equip legendary creature {2}

Power Fist

Equipped creature has trample and "Whenever this creature deals combat damage to a player, put that many +1/+1 counters on it."
Equip {2}

Forest

Mountain

Swamp

Archetype of Finality

Creatures you control have deathtouch.
Creatures your opponents control lose deathtouch and can't have or gain deathtouch.

Arachnoform

Enchant creature
Enchanted creature gets +2/+2, has reach, and is every creature type.

Misty Rainforest

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Mage Slayer

Whenever equipped creature attacks, it deals damage equal to its power to the player or planeswalker it's attacking.
Equip {3}

Belt of Giant Strength

Equipped creature has base power and toughness 10/10.
Equip {10}. This ability costs {X} less to activate, where X is the power of the creature it targets.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Gruul Turf

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Guardian Augmenter

Flash
Commander creatures you control get +2/+2.
Commanders you control have hexproof.

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Abundant Growth

Enchant land
When this Aura enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

Alloy Myr

Maarika, Brutal Gladiator

Maarika, Brutal Gladiator must be blocked if able.
As long as it's your turn, Maarika has indestructible.
Whenever Maarika deals damage to a creature, if that creature was dealt excess damage this turn, that creature's controller sacrifices a noncreature, nonland permanent.

Deathreap Ritual

Morbid — At the beginning of each end step, if a creature died this turn, you may draw a card.

Fiendlash

Equipped creature gets +2/+0 and has reach.
Whenever equipped creature is dealt damage, it deals damage equal to its power to target player or planeswalker.
Equip {2}{R}

Golgari Signet

Bigger on the Inside

Enchant artifact or land
Enchanted permanent has "{T}: Target player adds two mana of any one color. The next spell they cast this turn has cascade." (When they cast their next spell, they exile cards from the top of their library until they exile a nonland card that costs less. They may cast it without paying its mana cost. They put the exiled cards on the bottom in a random order.)

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Alpha Authority

Enchant creature
Enchanted creature has hexproof and can't be blocked by more than one creature.

Saryth, the Viper's Fang

Other tapped creatures you control have deathtouch.
Other untapped creatures you control have hexproof.
{1}, {T}: Untap another target creature or land you control.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Soul's Majesty

Draw cards equal to the power of target creature you control.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Golgari Rot Farm

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Rakdos Signet

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

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}

Altar of the Pantheon

Your devotion to each color and each combination of colors is increased by one.
{T}: Add one mana of any color. If you control a God, a Demigod, or a legendary enchantment, you gain 1 life.

Colossus Hammer

Equipped creature gets +10/+10 and loses flying.
Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)

Archetype of Endurance

Creatures you control have hexproof.
Creatures your opponents control lose hexproof and can't have or gain hexproof.

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Aspect of Lamprey

Enchant creature you control
When this Aura enters, target opponent discards two cards.
Enchanted creature has lifelink.

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Sword of Vengeance

Equipped creature gets +2/+0 and has first strike, vigilance, trample, and haste.
Equip {3}

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Glissa Sunslayer

First strike, deathtouch
Whenever Glissa Sunslayer deals combat damage to a player, choose one —
• You draw a card and you lose 1 life.
• Destroy target enchantment.
• Remove up to three counters from target permanent.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Aspect of Gorgon

Enchant creature
Enchanted creature gets +1/+3 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy it.)

Eternal Thirst

Enchant creature
Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Neyith of the Dire Hunt

Whenever one or more creatures you control fight or become blocked, draw a card.
At the beginning of combat on your turn, you may pay {2}{R/G}. If you do, double target creature's power until end of turn. That creature must be blocked this combat if able. ({R/G} can be paid with either {R} or {G}.)

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Toralf's Hammer

Equipped creature has "{1}{R}, {T}, Unattach Toralf's Hammer: It deals 3 damage to any target. Return Toralf's Hammer to its owner's hand."
Equipped creature gets +3/+0 as long as it's legendary.
Equip {1}{R}

Toralf, God of Fury

Trample
Whenever a creature or planeswalker an opponent controls is dealt excess noncombat damage, Toralf deals damage equal to the excess to any target other than that permanent.

Toralf, God of Fury // Toralf's Hammer

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Temple of Aclazotz

(Transforms from Arguel's Blood Fast.)
{T}: Add {B}.
{T}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Arguel's Blood Fast

{1}{B}, Pay 2 life: Draw a card.
At the beginning of your upkeep, if you have 5 or less life, you may transform Arguel's Blood Fast.