Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Dread Whispers

You draw a card and you lose 1 life. (Then exile this card. You may cast the creature later from exile.)

Mosswood Dreadknight

Trample
When this creature dies, you may cast it from your graveyard as an Adventure until the end of your next turn.

Mosswood Dreadknight // Dread Whispers

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Villainous Wealth

Target opponent exiles the top X cards of their library. You may cast any number of spells with mana value X or less from among them without paying their mana costs.

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Hydroid Krasis

When you cast this spell, you gain half X life and draw half X cards. Round down each time.
Flying, trample
This creature enters with X +1/+1 counters on it.

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.