Book Burning

Any player may have Book Burning deal 6 damage to them. If no one does, target player mills six cards.

Anurid Barkripper

Threshold — This creature gets +2/+2 as long as there are seven or more cards in your graveyard.

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Krosan Restorer

{T}: Untap target land.
Threshold — {T}: Untap up to three target lands. Activate only if there are seven or more cards in your graveyard.

Krosan Avenger

Trample
Threshold — {1}{G}: Regenerate this creature. Activate only if there are seven or more cards in your graveyard.

Mountain

Nimble Mongoose

Shroud (This creature can't be the target of spells or abilities.)
Threshold — This creature gets +2/+2 as long as there are seven or more cards in your graveyard.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Springing Tiger

Shriekhorn

This artifact enters with three charge counters on it.
{T}, Remove a charge counter from this artifact: Target player mills two cards.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Grapple with the Past

Mill three cards, then you may return a creature or land card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Song of Blood

Mill four cards. Whenever a creature attacks this turn, it gets +1/+0 until end of turn for each creature card put into your graveyard this way.

Forest

Wasteful Harvest

Mill five cards. You may put a permanent card from among the cards milled this way into your hand. (To mill a card, put the top card of your library into your graveyard.)

Werebear

{T}: Add {G}.
Threshold — This creature gets +3/+3 as long as there are seven or more cards in your graveyard.