Chittering Witch

When Chittering Witch enters, create a number of 1/1 black Rat creature tokens equal to the number of opponents you have.
{1}{B}, Sacrifice a creature: Target creature gets -2/-2 until end of turn.

Kodama of the East Tree

Reach
Whenever another permanent you control enters, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield.
Partner (You can have two commanders if both have partner.)

Shared Summons

Search your library for up to two creature cards with different names, reveal them, put them into your hand, then shuffle.

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Breach the Multiverse

Each player mills ten cards. For each player, choose a creature or planeswalker card in that player's graveyard. Put those cards onto the battlefield under your control. Then each creature you control becomes a Phyrexian in addition to its other types.

Henry Wu, InGen Geneticist

Henry Wu, InGen Geneticist and other Human creatures you control have exploit. (When a creature with exploit enters, you may sacrifice a creature.)
Whenever a creature you control exploits a non-Human creature, draw a card. If the exploited creature had power 3 or greater, create a Treasure token.

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker of their choice.

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.

Exploration

You may play an additional land on each of your turns.

Muldrotha, the Gravetide

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Culling Ritual

Destroy each nonland permanent with mana value 2 or less. Add {B} or {G} for each permanent destroyed this way.

Druid of Purification

When Druid of Purification enters, starting with you, each player may choose an artifact or enchantment you don't control. Destroy each permanent chosen this way.

Damnation

Destroy all creatures. They can't be regenerated.

Birds of Paradise

Expropriate

Council's dilemma — Starting with you, each player votes for time or money. For each time vote, take an extra turn after this one. For each money vote, choose a permanent owned by the voter and gain control of it. Exile Expropriate.

Disciples of Gix

When Disciples of Gix enters, search your library for up to three artifact cards, put them into your graveyard, then shuffle.

Time Stretch

Target player takes two extra turns after this one.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Ghostly Castigator

Flying
When Ghostly Castigator enters, you may shuffle up to three target cards from your graveyard into your library.
If Ghostly Castigator would be put into a graveyard from anywhere, exile it instead.

Covetous Castaway

When Covetous Castaway dies, mill three cards. (Put the top three cards of your library into your graveyard.)
Disturb {3}{U}{U} (You may cast this card from your graveyard transformed for its disturb cost.)