Sage of Mysteries

Constellation — Whenever an enchantment you control enters, target player mills two cards.

Island

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Plains

Soporific Springs

As Soporific Springs enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment you control enters, each opponent loses 1 life.

Go for the Throat

Murkwater Pathway

Clearwater Pathway

Clearwater Pathway // Murkwater Pathway

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Scrabbling Skullcrab

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, target player mills two cards. (They put the top two cards of their library into their graveyard.)

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Intimidation Campaign

When Intimidation Campaign enters, each opponent loses 1 life, you gain 1 life, and you draw a card.
Whenever you commit a crime, you may return Intimidation Campaign to its owner's hand. (It returns only from the battlefield. Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Disinformation Campaign

When Disinformation Campaign enters, you draw a card and each opponent discards a card.
Whenever you surveil, return Disinformation Campaign to its owner's hand.

Skullsnap Nuisance

Flying
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Cut Down

Destroy target creature with total power and toughness 5 or less.

Counterspell

Swamp

Archon of Sun's Grace

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Pegasus creatures you control have lifelink.
Constellation — Whenever an enchantment you control enters, create a 2/2 white Pegasus creature token with flying.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)