Oona's Gatewarden

Defender, flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Dihada's Ploy

Draw two cards, then discard a card. You gain life equal to the number of cards you've discarded this turn.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Swamp

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Dimir Cluestone

{T}: Add {U} or {B}.
{U}{B}, {T}, Sacrifice this artifact: Draw a card.

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Malicious Advice

Tap X target artifacts, creatures, and/or lands. You lose X life.

Island

Mistvault Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {B}.

Tidehollow Strix

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Soul Manipulation

Choose one or both —
• Counter target creature spell.
• Return target creature card from your graveyard to your hand.

Dash Hopes

When you cast this spell, any player may pay 5 life. If a player does, counter Dash Hopes.
Counter target spell.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Contaminated Bond

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Whenever enchanted creature attacks or blocks, its controller loses 3 life.