Kosei, Penitent Warlord

As long as Kosei, Penitent Warlord is enchanted, equipped, and has a counter on it, Kosei has "Whenever Kosei, Penitent Warlord deals combat damage to an opponent, you draw that many cards and Kosei deals that much damage to each other opponent."

Indomitable Might

Flash
Enchant creature
Enchanted creature gets +3/+3.
Enchanted creature's controller may have it assign its combat damage as though it weren't blocked.

Rune of Might

Enchant permanent
When Rune of Might enters the battlefield, draw a card.
As long as enchanted permanent is a creature, it gets +1/+1 and has trample.
As long as enchanted permanent is an Equipment, it has "Equipped creature gets +1/+1 and has trample."

Citanul Stalwart

{T}, Tap an untapped artifact or creature you control: Add one mana of any color.

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

Hydra's Growth

Enchant creature
When Hydra's Growth enters the battlefield, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

Ancestral Mask

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

Loxodon Warhammer

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

Guardian Augmenter

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

Ordeal of Nylea

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Nylea.
When you sacrifice Ordeal of Nylea, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Spider Umbra

Enchant creature
Enchanted creature gets +1/+1 and has reach. (It can block creatures with flying.)
Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

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.

Visions of Dominance

Put a +1/+1 counter on target creature, then double the number of +1/+1 counters on it.
Flashback {8}{G}{G}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Hero's Blade

Equipped creature gets +3/+2.
Whenever a legendary creature enters the battlefield under your control, you may attach Hero's Blade to it.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Elvish Mystic

Glowcap Lantern

Equipped creature has "You may look at the top card of your library any time" and "Whenever this creature attacks, it explores." (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)
Equip {2}

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Ring of Kalonia

Equipped creature has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's green.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Sigil of Distinction

Sigil of Distinction enters the battlefield with X charge counters on it.
Equipped creature gets +1/+1 for each charge counter on Sigil of Distinction.
Equip—Remove a charge counter from Sigil of Distinction.

Snake Umbra

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals damage to an opponent, you may draw a card."
Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Leather Armor

Equipped creature gets +0/+1 and has ward {1}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {0}. Activate only once each turn.

Bone Sabres

Whenever equipped creature attacks, put four +1/+1 counters on it.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Treefolk Umbra

Enchant creature
Enchanted creature gets +0/+2 and assigns combat damage equal to its toughness rather than its power.
Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If Incubation Druid has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

Blanchwood Armor

Enchant creature
Enchanted creature gets +1/+1 for each Forest you control.

Keen Sense

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Blade of the Bloodchief

Whenever a creature dies, put a +1/+1 counter on equipped creature. If equipped creature is a Vampire, put two +1/+1 counters on it instead.
Equip {1}

Tanuki Transplanter

Whenever Tanuki Transplanter or equipped creature attacks, add an amount of {G} equal to its power. Until end of turn, you don't lose this mana as steps and phases end.
Reconfigure {3} ({3}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Mark of Sakiko

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, add that much {G}. Until end of turn, you don't lose this mana as steps and phases end."

Colossification

Enchant creature
When Colossification enters the battlefield, tap enchanted creature.
Enchanted creature gets +20/+20.

Nettlecyst

Living weapon (When this Equipment enters the battlefield, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Gaea's Gift

Put a +1/+1 counter on target creature you control. It gains reach, trample, hexproof, and indestructible until end of turn. (It can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Armory of Iroas

Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

One with Nature

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Alpha Authority

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

Staff of Titania

Equipped creature gets +X/+X, where X is the number of Forests you control.
Whenever equipped creature attacks, create a 1/1 green Forest Dryad land creature token. (It's affected by summoning sickness.)
Equip {3}

Druid of the Cowl

Sol Ring

Drannith Ruins

{T}: Add {C}.
{2}, {T}: Put two +1/+1 counters on target non-Human creature that entered the battlefield this turn.

Royal Treatment

Target creature you control gains hexproof until end of turn. Create a Royal Role token attached to that creature. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has ward {1}.)

Oran-Rief, the Vastwood

Oran-Rief, the Vastwood enters the battlefield tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered the battlefield this turn.

Ancient Animus

Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Bedrock Tortoise

As long as it's your turn, creatures you control have hexproof.
Each creature you control with toughness greater than its power assigns combat damage equal to its toughness rather than its power.

Sword of Hours

Whenever equipped creature attacks, put a +1/+1 counter on it.
Whenever equipped creature deals combat damage, roll a d12. If the result is greater than the damage dealt or the result is 12, double the number of +1/+1 counters on that creature.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Hero's Heirloom

Equipped creature gets +2/+1.
As long as equipped creature is legendary, it has trample and haste.
Equip {2}

Predatory Hunger

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

Forest

Llanowar Elves

Thought Vessel

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

Fetch Quest

Mill seven cards. Then put a creature, enchantment, or land card from among the milled cards onto the battlefield.

Bramble Familiar

{T}: Add {G}.
{1}{G}, {T}, Discard a card: Return Bramble Familiar to its owner's hand.

Bramble Familiar // Fetch Quest

Leaf Gilder

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

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.)

Primal Bellow

Target creature gets +1/+1 until end of turn for each Forest you control.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Season of Growth

Whenever a creature enters the battlefield under your control, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)
Whenever you cast a spell that targets a creature you control, draw a card.

Forced Adaptation

Enchant creature
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature.

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand.

Shape of the Wiitigo

Enchant creature
When Shape of the Wiitigo enters the battlefield, put six +1/+1 counters on enchanted creature.
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature if it attacked or blocked since your last upkeep. Otherwise, remove a +1/+1 counter from it.

Fyndhorn Elves

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Forge of Heroes

{T}: Add {C}.
{T}: Choose target commander that entered the battlefield this turn. Put a +1/+1 counter on it if it's a creature and a loyalty counter on it if it's a planeswalker.

Blackblade Reforged

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

Thran Power Suit

Equipped creature gets +1/+1 for each Aura and Equipment attached to it and has ward {2}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)