Null Brooch

{2}, {T}, Discard your hand: Counter target noncreature spell.

Crown of Doom

Whenever a creature attacks you or a planeswalker you control, it gets +2/+0 until end of turn.
{2}: Target player other than Crown of Doom's owner gains control of it. Activate only during your turn.

Rendmaw, Creaking Nest

Menace, reach
When Rendmaw, Creaking Nest enters and whenever you play a card with two or more card types, each player creates a tapped 2/2 black Bird creature token with flying. The tokens are goaded for the rest of the game. (They attack each combat if able and attack a player other than you if able.)

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

Power Depot

Power Depot enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast artifact spells or activate abilities of artifacts.
Modular 1

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Golgari Signet

Scene of the Crime

Scene of the Crime enters tapped.
{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.
{2}, Sacrifice Scene of the Crime: Draw a card.

Darkmoss Bridge

Darkmoss Bridge enters tapped.
Indestructible
{T}: Add {B} or {G}.

Tree of Tales

Kuldotha Forgemaster

{T}, Sacrifice three artifacts: Search your library for an artifact card, put it onto the battlefield, then shuffle.

Sol Ring

Canoptek Spyder

Flying
Fabricator Claw Array — Whenever another nontoken artifact creature or Vehicle you control enters, draw a card.

Birthing Pod

({G/P} can be paid with either {G} or 2 life.)
{1}{G/P}, {T}, Sacrifice a creature: Search your library for a creature card with mana value equal to 1 plus the sacrificed creature's mana value, put that card onto the battlefield, then shuffle. Activate only as a sorcery.

Emerald Medallion

Green spells you cast cost {1} less to cast.

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Wishclaw Talisman

Wishclaw Talisman enters with three wish counters on it.
{1}, {T}, Remove a wish counter from Wishclaw Talisman: Search your library for a card, put it into your hand, then shuffle. An opponent gains control of Wishclaw Talisman. Activate only during your turn.

Vault of Whispers

Karn's Sylex

Karn's Sylex enters tapped.
Players can't pay life to cast spells or to activate abilities that aren't mana abilities.
{X}, {T}, Exile Karn's Sylex: Destroy each nonland permanent with mana value X or less. Activate only as a sorcery.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Adaptive Automaton

As Adaptive Automaton enters, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Jet Medallion

Black spells you cast cost {1} less to cast.

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As Obelisk of Urd enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Thran Dynamo

Arcane Signet

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

Ashnod's Altar

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Umori, the Collector

Companion — Each nonland card in your starting deck shares a card type. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
As Umori, the Collector enters, choose a card type.
Spells you cast of the chosen type cost {1} less to cast.

Darksteel Citadel

Sceptre of Eternal Glory

{T}: Add one mana of any color.
{T}: Add three mana of any one color. Activate only if you control three or more lands with the same name.