Standard Bearer

While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.

Bladeback Sliver

Hellbent — As long as you have no cards in hand, Sliver creatures you control have "{T}: This creature deals 1 damage to target player or planeswalker."

Forest

Heart Sliver

Thriving Grove

Thriving Grove enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Crimson Acolyte

Protection from red
{W}: Target creature gains protection from red until end of turn.

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.)

Obsidian Acolyte

Protection from black
{W}: Target creature gains protection from black until end of turn.

Sinew Sliver

Lead the Stampede

Look at the top five cards of your library. You may reveal any number of creature cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in any order.

Plains

Hunter Sliver

All Sliver creatures have provoke. (Whenever a Sliver attacks, its controller may have target creature defending player controls untap and block it if able.)

Predatory Sliver

Winding Way

Choose creature or land. Reveal the top four cards of your library. Put all cards of the chosen type revealed this way into your hand and the rest into your graveyard.

Plated Sliver

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Mountain

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Muscle Sliver

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.)

Bloodfire Dwarf

{R}, Sacrifice Bloodfire Dwarf: It deals 1 damage to each creature without flying.