Moment of Heroism

Target creature gets +2/+2 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Lancer Sliver

Sliver creatures you control have first strike.

Spiteful Sliver

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

Two-Headed Sliver

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

Enduring Sliver

Outlast {2} ({2}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Other Sliver creatures you control have outlast {2}.

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

For the Emperor!

Creatures you control get +2/+2 and gain vigilance and lifelink until end of turn.

Tenacity

Creatures you control get +1/+1 and gain lifelink until end of turn. Untap those creatures. (Damage dealt by those creatures also causes you to gain that much life.)

Sentinel Sliver

Sliver creatures you control have vigilance. (Attacking doesn't cause them to tap.)

Crystalline Sliver

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

Invigorated Rampage

Choose one —
• Target creature gets +4/+0 and gains trample until end of turn.
• Two target creatures each get +2/+0 and gain trample until end of turn.

Blade Sliver

Lavabelly Sliver

Sliver creatures you control have "When this creature enters, it deals 1 damage to target player or planeswalker and you gain 1 life."

Horn of the Mark

Whenever two or more creatures you control attack a player, look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Sinew Sliver

Run Amok

Target attacking creature gets +3/+3 and gains trample until end of turn.

Plains

Brute Force

Target creature gets +3/+3 until end of turn.

Essence Sliver

Whenever a Sliver deals damage, its controller gains that much life.

Vexing Bauble

Whenever a player casts a spell, if no mana was spent to cast it, counter that spell.
{1}, {T}, Sacrifice Vexing Bauble: Draw a card.

Cleaving Sliver

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Take Up the Shield

Put a +1/+1 counter on target creature. It gains lifelink and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Mountain

Capricious Sliver

Sliver creatures you control have "Whenever this creature deals combat damage to a player, exile the top card of your library. You may play that card this turn."

Bonescythe Sliver

Sliver creatures you control have double strike. (They deal both first-strike and regular combat damage.)

Striking Sliver

Sliver creatures you control have first strike. (They deal combat damage before creatures without first strike.)

Rally the Ranks

As Rally the Ranks enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.