Forensic Researcher

{T}: Untap another target permanent you control.
{T}, Collect evidence 3: Tap target creature you don't control. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

Kiora, the Rising Tide

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Lost in the Maze

Flash
When this enchantment enters, tap X target creatures. Put a stun counter on each of those creatures you don't control. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Tapped creatures you control have hexproof.

Rona, Tolarian Obliterator

Trample
Whenever a source deals damage to Rona, that source's controller exiles a card from their hand at random. If it's a land card, you may put it onto the battlefield under your control. Otherwise, you may cast it without paying its mana cost.

Rona, Herald of Invasion

Whenever you cast a legendary spell, untap Rona.
{T}: Draw a card, then discard a card.
{5}{B/P}: Transform Rona. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.)

Rona, Herald of Invasion // Rona, Tolarian Obliterator

Vodalian Hexcatcher

Flash
Other Merfolk you control get +1/+1.
Sacrifice a Merfolk: Counter target noncreature spell unless its controller pays {1}.

Island

Fountainport

{T}: Add {C}.
{2}, {T}, Sacrifice a token: Draw a card.
{3}, {T}, Pay 1 life: Create a 1/1 blue Fish creature token.
{4}, {T}: Create a Treasure token.

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Deeproot Pilgrimage

Whenever one or more nontoken Merfolk you control become tapped, create a 1/1 blue Merfolk creature token with hexproof.

Unctus, Grand Metatect

Other blue creatures you control have "Whenever this creature becomes tapped, draw a card, then discard a card."
Other artifact creatures you control get +1/+1.
{U/P}: Until end of turn, target creature you control becomes a blue artifact in addition to its other colors and types. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Floodpits Drowner

Flash
Vigilance
When this creature enters, tap target creature an opponent controls and put a stun counter on it.
{1}{U}, {T}: Shuffle this creature and target creature with a stun counter on it into their owners' libraries.

Jace Reawakened

You can't cast Jace Reawakened during your first, second, or third turns of the game.
+1: Draw a card, then discard a card.
+1: You may exile a nonland card with mana value 3 or less from your hand. If you do, it becomes plotted.
−6: Until end of turn, whenever you cast a spell, copy it. You may choose new targets for the copy.

Tishana's Tidebinder

Flash
When this creature enters, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as this creature remains on the battlefield. (Mana abilities can't be targeted.)

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Lifecraft Engine

As this Vehicle enters, choose a creature type.
Vehicle creatures you control are the chosen creature type in addition to their other types.
Each creature you control of the chosen type other than this Vehicle gets +1/+1.
Crew 3

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.