Mountain

Spyglass Siren

Flying
When Spyglass Siren enters the battlefield, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

Staunch Crewmate

When Staunch Crewmate enters the battlefield, look at the top four cards of your library. You may reveal an artifact or Pirate card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Island

Proft's Eidetic Memory

When Proft's Eidetic Memory enters the battlefield, draw a card.
You have no maximum hand size.
At the beginning of combat on your turn, if you've drawn more than one card this turn, put X +1/+1 counters on target creature you control, where X is the number of cards you've drawn this turn minus one.

Seafaring Werewolf

Seafaring Werewolf can't be blocked.
Whenever Seafaring Werewolf deals combat damage to a player, draw a card.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Suspicious Stowaway

Suspicious Stowaway can't be blocked.
Whenever Suspicious Stowaway deals combat damage to a player, draw a card, then discard a card.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Suspicious Stowaway // Seafaring Werewolf

Thundering Falls

({T}: Add {U} or {R}.)
Thundering Falls enters the battlefield tapped.
When Thundering Falls enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Take the Fall

Target creature gets -1/-0 until end of turn. It gets -4/-0 until end of turn instead if you control an outlaw. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
Draw a card.

Step Between Worlds

Each player may shuffle their hand and graveyard into their library. Each player who does draws seven cards. Exile Step Between Worlds.
Plot {4}{U}{U} (You may pay {4}{U}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Spirebluff Canal

Spirebluff Canal enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Malcolm, the Eyes

Flying, haste
Whenever you cast your second spell each turn, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Inspired Idea

Cleave {3}{U}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Draw three cards. [Your maximum hand size is reduced by three for the rest of the game.]

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Kitesail Larcenist

Flying, ward {1}
When Kitesail Larcenist enters the battlefield, for each player, choose up to one other target artifact or creature that player controls. For as long as Kitesail Larcenist remains on the battlefield, the chosen permanents become Treasure artifacts with "{T}, Sacrifice this artifact: Add one mana of any color" and lose all other abilities.

Discerning Peddler

When Discerning Peddler enters the battlefield, you may discard a card. If you do, draw a card.

Stormcarved Coast

Stormcarved Coast enters the battlefield tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Hellspur Brute

Affinity for outlaws (This spell costs {1} less to cast for each Assassin, Mercenary, Pirate, Rogue, and/or Warlock you control.)
Trample