Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Ancient Stirrings

Look at the top five cards of your library. You may reveal a colorless card from among them and put it into your hand. Then put the rest on the bottom of your library in any order.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Forest

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Torpor Orb

Creatures entering don't cause abilities to trigger.

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Swamp

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Lurrus of the Dream-Den

Companion — Each permanent card in your starting deck has mana value 2 or less. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Lifelink
Once during each of your turns, you may cast a permanent spell with mana value 2 or less from your graveyard.

Hangarback Walker

Hangarback Walker enters with X +1/+1 counters on it.
When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.
{1}, {T}: Put a +1/+1 counter on Hangarback Walker.

Darksteel Citadel

Veil of Summer

Draw a card if an opponent has cast a blue or black spell this turn. Spells you control can't be countered this turn. You and permanents you control gain hexproof from blue and from black until end of turn. (You and they can't be the targets of blue or black spells or abilities your opponents control.)

Damping Sphere

If a land is tapped for two or more mana, it produces {C} instead of any other type and amount.
Each spell a player casts costs {1} more to cast for each other spell that player has cast this turn.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Inkmoth Nexus

{T}: Add {C}.
{1}: Inkmoth Nexus becomes a 1/1 Phyrexian Blinkmoth artifact creature with flying and infect until end of turn. It's still a land. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Arcbound Worker

Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Phyrexia's Core

{T}: Add {C}.
{1}, {T}, Sacrifice an artifact: You gain 1 life.

Throne of Geth

{T}, Sacrifice an artifact: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Animation Module

Whenever one or more +1/+1 counters are put on a permanent you control, you may pay {1}. If you do, create a 1/1 colorless Servo artifact creature token.
{3}, {T}: Choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Arcbound Ravager

Sacrifice an artifact: Put a +1/+1 counter on Arcbound Ravager.
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Blooming Marsh

Blooming Marsh enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {G}.

Nurturing Peatland

{T}, Pay 1 life: Add {B} or {G}.
{1}, {T}, Sacrifice Nurturing Peatland: Draw a card.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Llanowar Reborn

Llanowar Reborn enters tapped.
{T}: Add {G}.
Graft 1 (This land enters with a +1/+1 counter on it. Whenever a creature enters, you may move a +1/+1 counter from this land onto it.)