Golden-Tail Trainer

Aura and Equipment spells you cast cost {X} less to cast, where X is Golden-Tail Trainer's power.
Whenever Golden-Tail Trainer attacks, other modified creatures you control get +X/+X until end of turn, where X is Golden-Tail Trainer's power. (Equipment, Auras you control, and counters are modifications.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Haunted Cloak

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

Island

Plains

Lathiel, the Bounteous Dawn

Lifelink
At the beginning of each end step, if you gained life this turn, distribute up to that many +1/+1 counters among any number of other target creatures.

Chariot of Victory

Equipped creature has first strike, trample, and haste.
Equip {1}

Aarakocra Sneak

Flying
When Aarakocra Sneak enters, you take the initiative.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Vedalken Humiliator

Metalcraft — Whenever Vedalken Humiliator attacks, if you control three or more artifacts, creatures your opponents control lose all abilities and have base power and toughness 1/1 until end of turn.

Werefox Bodyguard

Flash
When Werefox Bodyguard enters, exile up to one other target non-Fox creature until Werefox Bodyguard leaves the battlefield.
{1}{W}, Sacrifice Werefox Bodyguard: You gain 2 life.

Rune-Tail's Essence

Prevent all damage that would be dealt to creatures you control.

Rune-Tail, Kitsune Ascendant

When you have 30 or more life, flip Rune-Tail, Kitsune Ascendant.

Rune-Tail, Kitsune Ascendant // Rune-Tail's Essence

Simic Ascendancy

{1}{G}{U}: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy.
At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

Predatory Hunger

Enchant creature
Whenever an opponent casts a creature spell, put a +1/+1 counter on enchanted creature.

Blade-Blizzard Kitsune

Ninjutsu {3}{W} ({3}{W}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Double strike

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever Key to the City becomes untapped, you may pay {2}. If you do, draw a card.

Pearl-Ear, Imperial Advisor

Lifelink
Enchantment spells you cast have affinity for Auras. (They cost {1} less to cast for each Aura you control.)
Whenever you cast an Aura spell that targets a modified permanent you control, draw a card. (Equipment, Auras you control, and counters are modifications.)

Finest Hour

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, if it's the first combat phase of the turn, untap that creature. After this phase, there is an additional combat phase.

Codsworth, Handy Helper

Commanders you control have ward {2}.
{T}: Add {W}{W}. Spend this mana only to cast Aura and/or Equipment spells.
{T}: Attach target Aura or Equipment you control to target creature you control. Activate only as a sorcery.

Concerted Effort

At the beginning of each upkeep, creatures you control gain flying until end of turn if a creature you control has flying. The same is true for fear, first strike, double strike, landwalk, protection, trample, and vigilance.

Cephalid Facetaker

Cephalid Facetaker can't be blocked.
At the beginning of combat on your turn, you may have Cephalid Facetaker become a copy of another target creature until end of turn, except it's 1/4 and has "This creature can't be blocked."

Light-Paws, Emperor's Voice

Whenever an Aura you control enters, if you cast it, you may search your library for an Aura card with mana value less than or equal to that Aura and with a different name than each Aura you control, put that card onto the battlefield attached to Light-Paws, Emperor's Voice, then shuffle.

Thundering Mightmare

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Thundering Mightmare is paired with another creature, each of those creatures has "Whenever an opponent casts a spell, put a +1/+1 counter on this creature."

Eight-and-a-Half-Tails

{1}{W}: Target permanent you control gains protection from white until end of turn.
{1}: Target spell or permanent becomes white until end of turn.

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Sunscorch Regent

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Sunscorch Regent and you gain 1 life.

Samurai of the Pale Curtain

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
If a permanent would be put into a graveyard, exile it instead.

Cephalid Constable

Whenever Cephalid Constable deals combat damage to a player, return up to that many target permanents that player controls to their owner's hand.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Mantle of the Ancients

Enchant creature you control
When Mantle of the Ancients enters, return any number of target Aura and/or Equipment cards from your graveyard to the battlefield attached to enchanted creature.
Enchanted creature gets +1/+1 for each Aura and Equipment attached to it.

Mr. Foxglove

Lifelink
Whenever Mr. Foxglove attacks, draw cards equal to the number of cards in defending player's hand minus the number of cards in your hand. If you didn't draw cards this way, you may put a creature card from your hand onto the battlefield.

Ishai, Ojutai Dragonspeaker

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Ishai, Ojutai Dragonspeaker.
Partner (You can have two commanders if both have partner.)

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Rampant Growth

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

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Forest

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)