Counterspell

Oboro, Palace in the Clouds

{T}: Add {U}.
{1}: Return Oboro, Palace in the Clouds to its owner's hand.

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Patron of the Moon

Moonfolk offering (You may cast this spell any time you could cast an instant by sacrificing a Moonfolk and paying the difference in mana costs between this and the sacrificed Moonfolk. Mana cost includes color.)
Flying
{1}: Put up to two land cards from your hand onto the battlefield tapped.

Oboro Breezecaller

Flying
{2}, Return a land you control to its owner's hand: Untap target land.

Grazing Gladehart

Landfall — Whenever a land you control enters, you may gain 2 life.

Island

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

Soratami Mindsweeper

Flying
{2}, Return a land you control to its owner's hand: Target player mills two cards.

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Exploration

You may play an additional land on each of your turns.

Eternity Vessel

Eternity Vessel enters with X charge counters on it, where X is your life total.
Landfall — Whenever a land you control enters, you may have your life total become the number of charge counters on Eternity Vessel.

Scapeshift

Sacrifice any number of lands. Search your library for up to that many land cards, put them onto the battlefield tapped, then shuffle.