Winnowing

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
For each player, you choose a creature that player controls. Then each player sacrifices all other creatures they control that don't share a creature type with the chosen creature they control.

Twilight Diviner

When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Whenever one or more other creatures you control enter, if they entered or were cast from a graveyard, create a token that's a copy of one of them. This ability triggers only once each turn.

Chronicle of Victory

As Chronicle of Victory enters, choose a creature type.
Creatures you control of the chosen type get +2/+2 and have first strike and trample.
Whenever you cast a spell of the chosen type, draw a card.

Glen Elendra's Answer

This spell can't be countered.
Counter all spells your opponents control and all abilities your opponents control. Create a 1/1 blue and black Faerie creature token with flying for each spell and ability countered this way.

Soul Immolation

As an additional cost to cast this spell, blight X. X can't be greater than the greatest toughness among creatures you control. (Put X -1/-1 counters on a creature you control.)
Soul Immolation deals X damage to each opponent and each creature they control.

Sapling Nursery

Affinity for Forests (This spell costs {1} less to cast for each Forest you control.)
Landfall — Whenever a land you control enters, create a 3/4 green Treefolk creature token with reach.
{1}{G}, Exile this enchantment: Treefolk and Forests you control gain indestructible until end of turn.

Gathering Stone

As this artifact enters, choose a creature type.
Spells you cast of the chosen type cost {1} less to cast.
When this artifact enters and at the beginning of your upkeep, look at the top card of your library. If it's a card of the chosen type, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it into your graveyard.

Selfless Safewright

Flash
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
When this creature enters, choose a creature type. Other permanents you control of that type gain hexproof and indestructible until end of turn.

Harmonized Crescendo

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Choose a creature type. Draw a card for each permanent you control of that type.