Spells and abilities your opponents control can't cause their controller to search their library.

-1: Target player mills four cards. Then exile each opponent's graveyard.

Defender

When Barrier of Bones enters the battlefield, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Despoiler of Souls can't block.

{B}{B}, Exile two other creature cards from your graveyard: Return Despoiler of Souls from your graveyard to the battlefield.

Whenever one or more cards are put into your graveyard from your library, Devourer of Memory gets +1/+1 until end of turn and can't be blocked this turn.

{1}{U}{B}: Mill a card.

Flying

Menace (This creature can't be blocked except by two or more creatures.)

Whenever you surveil, put a +1/+1 counter on Dimir Spybug.

Choose target creature. Mill three cards, then put a +1/+1 counter on that creature for each creature card in your graveyard.

{1}{U}, {T}: Target creature doesn't untap during its controller's next untap step.

{2}{B}, {T}: 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.)

When Lazav, the Multifarious enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

{X}: Lazav, the Multifarious becomes a copy of target creature card in your graveyard with mana value X, except its name is Lazav, the Multifarious, it's legendary in addition to its other types, and it has this ability.

Flying

Whenever Nightveil Sprite attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Scrapheap Scrounger can't block.

{1}{B}, Exile another creature card from your graveyard: Return Scrapheap Scrounger from your graveyard to the battlefield.

When Screeching Skaab enters the battlefield, mill two cards.

{T}: Add {B}.

Channel -- {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Defender

Whenever you surveil, put a +1/+1 counter on Thoughtbound Phantasm.

As long as Thoughtbound Phantasm has three or more +1/+1 counters on it, it can attack as though it didn't have defender.