Kamahl's Sledge deals 4 damage to target creature. Threshold — If seven or more cards are in your graveyard, instead Kamahl's Sledge deals 4 damage to that creature and 4 damage to that creature's controller.
When Petradon enters, exile two target lands. When Petradon leaves the battlefield, return the exiled cards to the battlefield under their owners' control. {R}: Petradon gets +1/+0 until end of turn.
First strike Threshold — As long as seven or more cards are in your graveyard, Possessed Barbarian gets +1/+1, is black, and has "{2}{B}, {T}: Destroy target red creature."
Choose target instant or sorcery spell that targets only a single permanent or player. Copy that spell for each other permanent or player the spell could target. Each copy targets a different one of those permanents and players.
Untap target creature with power less than the number of cards in your graveyard and gain control of it until end of turn. That creature gains haste until end of turn.
Protection from black At the beginning of your upkeep, sacrifice Anurid Scavenger unless you put a card from your graveyard on the bottom of your library.
Haste Threshold — As long as seven or more cards are in your graveyard, Centaur Chieftain has "When Centaur Chieftain enters, creatures you control get +1/+1 and gain trample until end of turn."
Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Threshold — If seven or more cards are in your graveyard, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.