Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

Jhoira, Weatherlight Corsair

Whenever Jhoira enters or attacks, target opponent reveals cards from the top of their library until they reveal a historic permanent card. You put that card onto the battlefield under your control and lose life equal to that permanent's mana value. That player puts the rest of the revealed cards on the bottom of their library in a random order. (Artifacts, legendaries, and Sagas are historic.)

Radiant Summit

({T}: Add {R} or {W}.)
This land enters tapped unless you control two or more basic lands.

Restless Anchorage

This land enters tapped.
{T}: Add {W} or {U}.
{1}{W}{U}: Until end of turn, this land becomes a 2/3 white and blue Bird creature with flying. It's still a land.
Whenever this land attacks, create a Map token.

Restless Spire

This land enters tapped.
{T}: Add {U} or {R}.
{U}{R}: Until end of turn, this land becomes a 2/1 blue and red Elemental creature with "During your turn, this creature has first strike." It's still a land.
Whenever this land attacks, scry 1.

Shivan Reef

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

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Sulfurous Springs

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

Sunken Ruins

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

Underground River

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

Omnath, Locus of the Void

Omnath gets +1/+1 for each unspent mana you have.
If you would lose unspent mana, that mana becomes colorless instead.
Landfall — Whenever a land you control enters, add {C}{C}.

Dack Fayden, Helping Hand

When Dack Fayden enters, reveal cards from the top of your library until you reveal X creature cards, where X is the number of opponents you have. Put those creature cards onto the battlefield, then shuffle. They're goaded for the rest of the game. For each of those permanents, choose a different opponent. Each opponent gains control of the permanent for which they were chosen.

Copy

Venser, Fervent Forger

Flash
When Venser enters, choose one —
• Copy target instant or sorcery spell an opponent controls twice. You may choose new targets for the copies.
• Create two tokens that are copies of target permanent an opponent controls. They gain haste. At the beginning of the next end step, sacrifice them.

Ob Nixilis, the Ascended

Angel

Flying
When Ob Nixilis enters, destroy all tapped creatures your opponents control. You gain 1 life for each creature destroyed this way.
At the beginning of each end step, if you gained life this turn, create a 4/4 white Angel creature token with flying.

Teferi's Reproach

Choose target opponent. Until that player's next turn, they gain protection from everything and their life total can't change. All nonland permanents they control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before that player untaps during their next untap step.)
Exile Teferi's Reproach.

Avacyn, Angel of Horror

Flying, deathtouch
Whenever Avacyn or another nontoken creature you control dies, return that card to the battlefield under your control at the beginning of the next end step.

Reality Fracture Commander