Scavenging Ooze

{G}: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on Scavenging Ooze and you gain 1 life.

Languish

All creatures get -4/-4 until end of turn.

Kaya's Guile

Choose two —
• Each opponent sacrifices a creature.
• Exile all opponents' graveyards.
• Create a 1/1 white and black Spirit creature token with flying.
• You gain 4 life.
Entwine {3} (Choose all if you pay the entwine cost.)

Maelstrom Pulse

Destroy target nonland permanent and all other permanents with the same name as that permanent.

Grim Flayer

Trample
Whenever Grim Flayer deals combat damage to a player, surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Delirium — Grim Flayer gets +2/+2 as long as there are four or more card types among cards in your graveyard.

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on Tireless Tracker.

Siege Rhino

Trample
When Siege Rhino enters, each opponent loses 3 life and you gain 3 life.

Knight of Autumn

When Knight of Autumn enters, choose one —
• Put two +1/+1 counters on Knight of Autumn.
• Destroy target artifact or enchantment.
• You gain 4 life.

Knight of the Reliquary

Knight of the Reliquary gets +1/+1 for each land card in your graveyard.
{T}, Sacrifice a Forest or Plains: Search your library for a land card, put it onto the battlefield, then shuffle.