Lymph Sliver

All Sliver creatures have absorb 1. (If a source would deal damage to a Sliver, prevent 1 of that damage.)

Sunlance

Sunlance deals 3 damage to target nonwhite creature.

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.)

Gone

Return target creature you don't control to its owner's hand.

Dead

Dead // Gone

Mountain

Virulent Sliver

All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)

Dryad Arbor

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Pulmonic Sliver

All Sliver creatures have flying.
All Slivers have "If this permanent would be put into a graveyard, you may put it on top of its owner's library instead."

Mana Tithe

Counter target spell unless its controller pays {1}.

Reflex 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.)

Watcher Sliver

Battering Sliver

Strength in Numbers

Until end of turn, target creature gains trample and gets +X/+X, where X is the number of attacking creatures.

Spinneret Sliver

Poultice Sliver

All Slivers have "{2}, {T}: Regenerate target Sliver." (The next time that Sliver would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Sinew Sliver

Forest

Bound in Silence

Enchant creature
Enchanted creature can't attack or block.

Fury Sliver

Fungal Reaches

{T}: Add {C}.
{1}, {T}: Put a storage counter on Fungal Reaches.
{1}, Remove X storage counters from Fungal Reaches: Add X mana in any combination of {R} and/or {G}.

Plains

Kher Keep

{T}: Add {C}.
{1}{R}, {T}: Create a 0/1 red Kobold creature token named Kobolds of Kher Keep.

Two-Headed Sliver

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)

Shivan Meteor

Shivan Meteor deals 13 damage to target creature.
Suspend 2—{1}{R}{R} (Rather than cast this card from your hand, you may pay {1}{R}{R} and exile it with two 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.)