This is a modern slivers tribal deck. This list has evolved a lot. This deck turns creatures sideways and grinds out wins. It has a lot of answers to most modern decks.
Main-board
The core of the deck are the three lords Predatory Sliver , Sinew Sliver , and Sedge Sliver. They pump up the team, including themselves. Sedge has the utility of regenerate, which is very valuable against creature decks. Sedge requires a swamp. That causes many issues in the mana base.
The rest of the creatures provide a utility to the team.
Diffusion Sliver
makes removal painful to cast and stacks with multiple creatures.
Manaweft Sliver
+ Gemhide Sliver fix the mana base and allow you to dump your hand.
Galerider Sliver
is the best value breakthrough card available. Necrotic Sliver is great spot removal. At eight mana, Sliver Hive provides a free Vindicate, per turn. Darkheart Sliver + Syphon Sliver provide life-gain, which is very useful in modern.
Screeching Sliver
is an alternative win condition.
The manabase is extremely awkward. Sliver Hive and Cavern of Souls are vital to casting everything. I run two basic land. This is to deal with Path to Exile and Blood Moon. From two basics a bunch of mountains, you can come back to win. The need for a Swamp is very taxing. Normally, I'll have a swamp by turn four. Red is the only color I can't fetch.
The other cards are to accelerate the deck. Collected Company can put you in winning position. Aether Vial allows you to accelerate casting and evades Eidolon of the Great Revel.
Matchups
Affinity
Affinity's game plan is to dump their and race the deck. A lot of their creatures have flying, so
Galerider Sliver
is very important. Affinity is unable to grow their board as well, so their late game draws are much worse that ours. Etched Champion can be hard to deal with, but can be blocked by Mutavault. Also, they may bring Blood Moon out of the sideboard. Chalice of the Void and Harmonic Sliver are huge out of the side board. If you are on the play, chalice for 0. If you are on the draw, it's better to not play chalice. Chalice on 2 can be really good, but taking turn 3/4 off could be too risky. Harmonic on turn 3 is usually game ending. Also, harmonic triggers stack. This means the second harmonic gets 2 naturalize triggers.
Jeskai Tempo/Control
The control player will not want you to resolve a single sliver. Their deck is full of counter spells, removal, and Snapcaster Mage to do it again. They will bring in Supreme Verdict . They may bring in Engineered Explosives or Izzet Staticaster . Cavern of Souls and Aether Vial make their counter spells useless, so expect your Collected Company to be countered. Diffusion Sliver and Frenetic Sliver make spot removal really hard to deal with. Also, Sedge Sliver can regenerate creatures from a verdict. This matchup is hard to navigate, but the deck is a stack of threats and is really hard for control to deal with.
Eldrazi Tron
The tron deck wants to play a couple big creatures that are hard to deal with. The deck grows faster that the tron deck. Their big threats are Reality Smasher , Walking Ballista , Karn Liberated , All Is Dust , and ugin, the prit dragon if they play him. The rest of their card are ok at best. Also, they might play Basilisk Collar out of the side. Necrotic Sliver can shut down their mana and creatures. Sedge Sliver is really good for the block and regenerate plan. Diffusion Sliver stops their ballista tricks. Galerider Sliver allows you to swing in.
RG Scapeshift/ Breach
The Scapeshift deck want to cast their namesake card and kill you with Valakut, the Molten Pinnacle. Their plan is to ramp up to scapeshift or through the breech they get valakut and some mountains. The key here is that 7 lands without Prismatic Omen is 18 damage. also, 8 land can be 36 damage. They play Anger of the Gods to sweep our board. The key is life gain and pressure the to find answers. Darkheart Sliver and Syphon Sliver can be hard with them to deal with. I have heard you can use the strategy of Necrotic Sliver as stone rain and use Telekinetic Sliver to constrict their mana.
Death's Shadow variants
The Death's Shadow deck are a faster tempo version of jund. They play lost of removal and interaction. They dump big creatures to pressure you. Sedge Sliver is really hard for them to deal with. They have to use Terminate and Diffusion Sliver will make them tappout for it. The block regenerate plan is really strong here. Chalice of the Void on 1 can shut down this deck. Also, Chameleon Colossus is immortal against them. This is a deck to bring the Sliver Hivelord in against.
Storm
Storm is a combo deck that casts a bunch of spells and a spell with storm like Grapeshot or Empty the Warrens. Their key helpers are Gifts Ungiven , Past in Flames , Goblin Electromancer , Baral, Chief of Compliance . You must get rid of their mana reducers. Nameless Inversion and Necrotic Sliver is your best way to do this. Chalice of the Void for 2 slows storm to a crawl. They will have Wipe Away out of the side to remove it. They will bring Blood Moon out of the side, so don't take out your red creatures.
Tron
Ugin, the Spirit Dragon , Karn Liberated , and Oblivion Stone are really good against this deck. The cards that stop tron is Necrotic Sliver to Stone Rain them and Telekinetic Sliver to Time Walk them. Frenetic Sliver should come in to avoid their board wipes. Harmonic Sliver can blow up their search pieces. Mindlash Sliver can be good at controlling their hand.
Taxes
The death or eldrazi and taxes decks are a good match-up. Their biggest creature is a 4/4 . Harmonic Sliver can take out their vials. Diffusion Sliver makes Eldrazi Displacer into a 3/3 vanilla. Galerider Sliver prevents them from blocking. The small amount of fetches makes Leonin Arbiter not as good.
Burn
Burn is a weird match up. Blocking is a really strong mechanic against burn. Eidolon of the Great Revel is probably their best against the deck. Lifegain is hard for them to deal with. Darkheart Sliver is too strong for them to deal with. Syphon Sliver can be really good as well. Chalice of the Void on 1 or 2 can be really strong but is weaker on the draw.
Lantern
This match up is won by your opponent not knowing your deck. Homing Sliver can find Necrotic Sliver or Harmonic Sliver to start destroying their board. Chalice of the Void on 1 stops their interaction. Screeching Sliver and Mindlash Sliver can make the deck mill them better than lantern.
Ad Nauseam
Ad Nas is a combo deck that casts Angel's Grace + Ad Nauseam to draw their whole deck and cast Lightning Storm for lethal. They use multiple artifacts to ramp their mana. They use diffrent Fog effects to slow you down. They will bring Path to Exile , Echoing Truth , Bontu's Last Reckoning out of the side. The main game plan is try and race them. You'll want to blow up their mana eggs with Harmonic Sliver or Necrotic Sliver . Chalice of the Void on 1 is good at slowing them down. Also, you can discard a land to lightning storm and redirect it to Diffusion Sliver to counter it.
Counters Company
Counters company is a combo deck that makes infinite mana with Devoted Druid and Vizier of Remedies. They can then cast all their creatures or a huge Walking Ballista. The deck runs no interaction. It just tries to push it's combo. Slivers has trouble with creation interaction quickly. Necrotic Sliver is the best removal spell in the main. Nameless Inversion and Warping Wail can remove their combo pieces. Once you have removed one, you should have enough time to race them.
Jund
Jund is a fun match up. They play lots of interaction and removal. Liliana of the Veil is pretty strong, but usually only get to live for a turn. Tarmogoyf can be blocked sometimes. Diffusion Sliver and Sedge Sliver really shine here. They prevent or negate removal. Frenetic Sliver , Chameleon Colossus, and Sliver Hivelord are good at dealing with the ineraction and blocking goyf. The is another deck that may run Blood Moon, so fetch basics and have red creatures.
Dredge
Dredge is named after the keyword that allows them to mill themselves instead of drawing. They get their creatures back from the graveyard and attack you. Their creatures are usually pretty small. Blocking is good against them. Conflagrate and Darkblast can be really good against us, so Diffusion Sliver should be on the field. The usual cards of Galerider Sliver and Sedge Sliver win this game.
Knightfall
This is a combo deck that uses Knight of the Reliquary and Retreat to Coralhelm to make a 19/19 knight and tap down your creatures. You have to destroy the combo pieces before they are both on the field because they can tap and make it a 19/19 at instant speed. This deck isn't super consistent, so the holding up Necrotic Sliver and swinging in with the team can be troublesome for them. Their sideboard has counterspells and Spell Queller . The queller can take your stuff casted off Cavern of Souls .
