Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Spined Sliver

Whenever a Sliver becomes blocked, that Sliver gets +1/+1 until end of turn for each creature blocking it.

High Priest of Penance

Whenever this creature is dealt damage, you may destroy target nonland permanent.

Fungus Sliver

All Sliver creatures have "Whenever this creature is dealt damage, put a +1/+1 counter on it." (It must survive the damage to get the counter.)

Might Sliver

Homing Sliver

Each Sliver card in each player's hand has slivercycling {3}.
Slivercycling {3} ({3}, Discard this card: Search your library for a Sliver card, reveal it, put it into your hand, then shuffle.)

Fury Sliver

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Sliver Legion

All Sliver creatures get +1/+1 for each other Sliver on the battlefield.

Frenzy Sliver

All Sliver creatures have frenzy 1. (Whenever a Sliver attacks and isn't blocked, it gets +1/+0 until end of turn.)

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Shifting Sliver

Slivers can't be blocked except by Slivers.

Quick Sliver

Flash
Any player may cast Sliver spells as though they had flash.

Harmonic Sliver

All Slivers have "When this permanent enters, destroy target artifact or enchantment."

Mana Leak

Counter target spell unless its controller pays {3}.

Mirri, Weatherlight Duelist

First strike
Whenever Mirri attacks, each opponent can't block with more than one creature this combat.
As long as Mirri is tapped, no more than one creature can attack you each combat.

Sidewinder Sliver

All Sliver creatures have flanking. (Whenever a creature without flanking blocks a Sliver, the blocking creature gets -1/-1 until end of turn.)

Brood Sliver

Whenever a Sliver deals combat damage to a player, its controller may create a 1/1 colorless Sliver creature token.

Crystalline Sliver

All Slivers have shroud. (They can't be the targets of spells or abilities.)

Serum Visions

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Sliver Overlord

{3}: Search your library for a Sliver card, reveal that card, put it into your hand, then shuffle.
{3}: Gain control of target Sliver. (This effect lasts indefinitely.)