Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Sol Ring

Solemnity

Players can't get counters.
Counters can't be put on artifacts, creatures, enchantments, or lands.

Tormod, the Desecrator

Whenever one or more cards leave your graveyard, create a tapped 2/2 black Zombie creature token.
Partner (You can have two commanders if both have partner.)

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Harvest Season

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, put those cards onto the battlefield tapped, then shuffle.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Golgari Signet

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Spawning Pit

Sacrifice a creature: Put a charge counter on Spawning Pit.
{1}, Remove two charge counters from Spawning Pit: Create a 2/2 colorless Spawn artifact creature token.

Fecundity

Whenever a creature dies, that creature's controller may draw a card.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Ashnod's Altar

Earthcraft

Tap an untapped creature you control: Untap target basic land.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Gravecrawler

Gravecrawler can't block.
You may cast Gravecrawler from your graveyard as long as you control a Zombie.

Melira, Sylvok Outcast

You can't get poison counters.
Creatures you control can't have -1/-1 counters put on them.
Creatures your opponents control lose infect.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Sidar Kondo of Jamuraa

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
Creatures your opponents control without flying or reach can't block creatures with power 2 or less.
Partner (You can have two commanders if both have partner.)