Mindleech Mass

Trample
Whenever this creature deals combat damage to a player, you may look at that player's hand. If you do, you may cast a spell from among those cards without paying its mana cost.

Island

Looter il-Kor

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever this creature deals damage to an opponent, draw a card, then discard a card.

Psychic Drain

Target player mills X cards and you gain X life.

Recoil

Return target permanent to its owner's hand. Then that player discards a card.

Dimir Aqueduct

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

Psychic Spiral

Shuffle all cards from your graveyard into your library. Target player mills that many cards.

Phthisis

Destroy target creature. Its controller loses life equal to its power plus its toughness.
Suspend 5—{1}{B} (Rather than cast this card from your hand, you may pay {1}{B} and exile it with five time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Induce Paranoia

Counter target spell. If {B} was spent to cast this spell, that spell's controller mills X cards, where X is the spell's mana value.

Blizzard Specter

Flying
Whenever this creature deals combat damage to a player, choose one —
• That player returns a permanent they control to its owner's hand.
• That player discards a card.

Nephalia Drownyard

{T}: Add {C}.
{1}{U}{B}, {T}: Target player mills three cards.

Dimir Infiltrator

This creature can't be blocked.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Dimir Guildmage

({U/B} can be paid with either {U} or {B}.)
{3}{U}: Target player draws a card. Activate only as a sorcery.
{3}{B}: Target player discards a card. Activate only as a sorcery.

Lazav, Dimir Mastermind

Hexproof
Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.

Undermine

Counter target spell. Its controller loses 3 life.

Darkwater Catacombs

Paranoid Delusions

Target player mills three cards.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Dimir Doppelganger

{1}{U}{B}: Exile target creature card from a graveyard. This creature becomes a copy of that card, except it has this ability.

Circu, Dimir Lobotomist

Whenever you cast a blue spell, exile the top card of target player's library.
Whenever you cast a black spell, exile the top card of target player's library.
Your opponents can't cast spells with the same name as a card exiled with Circu.

Swamp

Clutch of the Undercity

Return target permanent to its owner's hand. Its controller loses 3 life.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)