Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Forbidding Watchtower

Forbidding Watchtower enters tapped.
{T}: Add {W}.
{1}{W}: Forbidding Watchtower becomes a 1/5 white Soldier creature until end of turn. It's still a land.

Field of the Dead

Field of the Dead enters tapped.
{T}: Add {C}.
Whenever Field of the Dead or another land you control enters, if you control seven or more lands with different names, create a 2/2 black Zombie creature token.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Kjeldoran Outpost

If Kjeldoran Outpost would enter, sacrifice a Plains instead. If you do, put Kjeldoran Outpost onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {W}.
{1}{W}, {T}: Create a 1/1 white Soldier creature token.

Cave of the Frost Dragon

If you control two or more other lands, Cave of the Frost Dragon enters tapped.
{T}: Add {W}.
{4}{W}: Cave of the Frost Dragon becomes a 3/4 white Dragon creature with flying until end of turn. It's still a land.

Tomik, Distinguished Advokist

Flying
Lands on the battlefield and land cards in graveyards can't be the targets of spells or abilities your opponents control.
Your opponents can't play land cards from graveyards.

Cactus Preserve

Cactus Preserve enters tapped.
{T}: Add one mana of any type that a land you control could produce.
{3}: Until end of turn, Cactus Preserve becomes an X/X green Plant creature with reach, where X is the greatest mana value among your commanders. It's still a land.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Guardian Zendikon

Enchant land
Enchanted land is a 2/6 white Wall creature with defender. It's still a land.
When enchanted land dies, return that card to its owner's hand.

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Stalking Stones

{T}: Add {C}.
{6}: Stalking Stones becomes a 3/3 Elemental artifact creature that's still a land. (This effect lasts indefinitely.)

Vesuva

You may have Vesuva enter tapped as a copy of any land on the battlefield.

Terra Eternal

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.)

Planar Outburst

Destroy all nonland creatures.
Awaken 4—{5}{W}{W}{W} (If you cast this spell for {5}{W}{W}{W}, also put four +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Dread Statuary

{T}: Add {C}.
{4}: Dread Statuary becomes a 4/2 Golem artifact creature until end of turn. It's still a land.

Mobilized District

{T}: Add {C}.
{4}: Mobilized District becomes a 3/3 Citizen creature with vigilance until end of turn. It's still a land. This ability costs {1} less to activate for each legendary creature and planeswalker you control.

Mishra's Foundry

{T}: Add {C}.
{2}: Mishra's Foundry becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{1}, {T}: Target attacking Assembly-Worker gets +2/+2 until end of turn.

Hostile Desert

{T}: Add {C}.
{2}, Exile a land card from your graveyard: Hostile Desert becomes a 3/4 Elemental creature until end of turn. It's still a land.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Plains

Ondu Rising

Whenever a creature attacks this turn, it gains lifelink until end of turn.
Awaken 4—{4}{W} (If you cast this spell for {4}{W}, also put four +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Flagstones of Trokair

{T}: Add {W}.
When Flagstones of Trokair is put into a graveyard from the battlefield, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Wall of Resurgence

Defender
When Wall of Resurgence enters, you may put three +1/+1 counters on target land you control. If you do, that land becomes a 0/0 Elemental creature with haste that's still a land.

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Emeria, the Sky Ruin

Emeria, the Sky Ruin enters tapped.
At the beginning of your upkeep, if you control seven or more Plains, you may return target creature card from your graveyard to the battlefield.
{T}: Add {W}.

Mishra's Groundbreaker

{T}, Sacrifice Mishra's Groundbreaker: Target land becomes a 3/3 artifact creature that's still a land. (This effect lasts indefinitely.)

Minas Tirith

Minas Tirith enters tapped unless you control a legendary creature.
{T}: Add {W}.
{1}{W}, {T}: Draw a card. Activate only if you attacked with two or more creatures this turn.

Genju of the Fields

Enchant Plains
{2}: Until end of turn, enchanted Plains becomes a 2/5 white Spirit creature with "Whenever this creature deals damage, its controller gains that much life." It's still a land.
When enchanted Plains is put into a graveyard, you may return Genju of the Fields from your graveyard to your hand.