Keyword: Threshold

: Add . Barbarian Ring deals 1 damage to you.
Threshold — , , Sacrifice Barbarian Ring: It deals 2 damage to any target. Activate this ability only if seven or more cards are in your graveyard.

: Add .
Threshold — Werebear gets +3/+3 as long as seven or more cards are in your graveyard.

: Add .
Threshold — : Nantuko Monastery becomes a 4/4 green and white Insect Monk creature with first strike until end of turn. It’s still a land. Activate this ability only if seven or more cards are in your graveyard.

Protection from black
Threshold — As long as seven or more cards are in your graveyard, Mystic Enforcer gets +3/+3 and has flying.

, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can’t block.

, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can’t block.

Destroy all creatures. They can’t be regenerated.
Threshold — If seven or more cards are in your graveyard, instead destroy all creatures, then create two 1/1 white Spirit creature tokens with flying. Creatures destroyed this way can’t be regenerated.

, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can’t block.

, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can’t block.

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

: Add . Centaur Garden deals 1 damage to you.
Threshold — , , Sacrifice Centaur Garden: Target creature gets +3/+3 until end of turn. Activate this ability only if seven or more cards are in your graveyard.

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

: Add .
Threshold — Werebear gets +3/+3 as long as seven or more cards are in your graveyard.

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

Reach (This creature can block creatures with flying.)
Threshold — Seton’s Scout gets +2/+2 as long as seven or more cards are in your graveyard.

: Add . Cephalid Coliseum deals 1 damage to you.
Threshold — , , Sacrifice Cephalid Coliseum: Target player draws three cards, then discards three cards. Activate this ability only if seven or more cards are in your graveyard.

Flying
Threshold — Other creatures you control get +2/+2 as long as seven or more cards are in your graveyard.

Lightning Surge deals 4 damage to any target.
Threshold — If seven or more cards are in your graveyard, instead Lightning Surge deals 6 damage to that permanent or player and the damage can’t be prevented.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flying
Threshold — As long as seven or more cards are in your graveyard, Fledgling Dragon gets +3/+3 and has “: Fledgling Dragon gets +1/+0 until end of turn.”

Flying
Whenever Treacherous Vampire attacks or blocks, sacrifice it unless you exile a card from your graveyard.
Threshold — As long as seven or more cards are in your graveyard, Treacherous Vampire gets +2/+2 and has “When Treacherous Vampire dies, you lose 6 life.”

Target nonblack creature gets -1/-1 until end of turn.
Threshold — If seven or more cards are in your graveyard, instead destroy that creature. It can’t be regenerated.

Threshold — Anurid Barkripper gets +2/+2 as long as seven or more cards are in your graveyard.

Threshold — Put three cards from your graveyard on the bottom of your library: Battlefield Scrounger gets +3/+3 until end of turn. Activate this ability only once each turn and only if seven or more cards are in your graveyard.

Threshold — As long as seven or more cards are in your graveyard, Treacherous Werewolf gets +2/+2 and has “When Treacherous Werewolf dies, you lose 4 life.”

Threshold — As long as seven or more cards are in your graveyard, Hunting Grounds has “Whenever an opponent casts a spell, you may put a creature card from your hand onto the battlefield.”