Hidden Cataract

This land enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice this land: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hidden Nursery

This land enters tapped.
{T}: Add {G}.
{4}{G}, {T}, Sacrifice this land: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Selective Obliteration

Each player chooses a color. Then exile each permanent unless it's colorless or it's only the color its controller chose.

Izzet Boilerworks

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. This land deals 1 damage to you.

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Lair of the Hydra

If you control two or more other lands, this land enters tapped.
{T}: Add {G}.
{X}{G}: Until end of turn, this land becomes an X/X green Hydra creature. It's still a land. X can't be 0.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. This land deals 1 damage to you.

Lumbering Falls

This land enters tapped.
{T}: Add {G} or {U}.
{2}{G}{U}: Until end of turn, this land becomes a 3/3 green and blue Elemental creature with hexproof. It's still a land.

Lush Oasis

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {G} or {U}.

Mossfire Valley

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Eldrazi Scion

Spawnbed Protector

At the beginning of your end step, return up to one target Eldrazi creature card from your graveyard to your hand. Create two 1/1 colorless Eldrazi Scion creature tokens with "Sacrifice this token: Add {C}."

Mystic Monastery

This land enters tapped.
{T}: Add {U}, {R}, or {W}.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Modern Horizons 3 Commander