Q: First of all why did they make slivers so strong? And are they legal in tournaments? Is there a counter for slivers, please tell me the name of the deck.
A: Hello there!
Slivers have been out since Tempest, and have known a very limited success. I receive a lot of questions about Slivers in general, and I thought I could give you a little history class about Slivers on the competitive scene, from what I remember!
PT LA '98, Tempest Block Constructed (only Tempest at that time)
Ben Rubin piloted a Living Death deck featuring Mindwhip Sliver and Mnemonic Sliver to the finals of the tournament, eventually losing to David Price. During that tournament, I remember that Team CMU was playing a monogreen deck that included Metallic Slivers, Muscle Slivers and Horned Slivers along with Land Destruction This was the first opportunity Slivers could be played, and they haven't really shone much. Here's the list, courtesy of Randy's article "The Elephant and the Armodon". Buehler/Schneider's Iron City Beatdown
PT Chicago '99, Extended
Christian Luhrs took his Counter Sliver deck to the Top 8. Crystalline, Hibernation, Muscle, Winged and Acidic Slivers could be played on a Sunday, while I was myself bringing the Sliver Queen to the mix on another table on the same day.Christian Lührs's DD-Sliver
PT Chicago Top 8 - Extended Deck circa 1999
GP Montréal '07, Time Spiral Block Constructed
Guillaume Wafo Tapa brought the Slivers back to the top tables along with Wild Pair, a deck that had been played with less success during PT Yokohama a few months prior that tournament. Dormant, Frenetic, Reflex, Harmonic, Might, Darkheart, Gemhide, Telekinetic Slivers added their name to the "not so succesful in high level tournament" sliver family. (Necrotic Sliver is featuring in some versions of the deck as well.)Guillaume Wafo-Tapa's Sliver Pair
2007 GP Montreal Top 8
Other notable appearences:
French Nationals '98
Fabien Demazeau, an unknown player back then, who later became Worlds Team Finalist alongside Pierre Malherbaud, Marc Hernandez and Manuel Bevand, played an innovative 5 color sliver deck that took him to the top. He won Nationals with a deck packing only slivers and 3 Living Death (and very few other spells). Manuel, runner up of that tournament, lost a decisive game to Clot Sliver, which was able to save its brothers from a Nevinyral's Disk activation. Heart Sliver was there to support the champ too. At that time a counter sliver deck was also working quite fine, but here's the deck Fabien ran.Fabien Demazeau's 5C Slivers
Pro Tour Rome '99
A couple of french players showed up with a Necro Sliver deck (Necropotence and Slivers). No unknown slivers made it to the PT, but they saw play in a new setup.
Block Constructed PTQs '07
Poison Slivers became a popular deck lately in Block Constructed. Frank Karsten wrote a whole article about it last week so you might as well check that one. This one brings a bunch of new slivers to the top: Screeching, Virulent, Firewake and Homing slivers.
To actually answer the question: Slivers are not unfairly strong. With the bunch of them, we could have expected a lot more succesful decks. They are tournament legal, depending on when they have been printed. They obey to the same rules all the other cards do. There's no deck made to beat slivers in general, a finely tuned deck should beat your friend's sliver deck (that reminds me of a not so popular answer I gave some time ago!
I may miss a few sliver decks that appeared in GP Top 8s in Tempest Block Constructed back in '98, or in extended in '99. Decklists from back then are hard to retrieve! But I don't think I am making a major omission.
For another read about Slivers, check BDM's article from March '04!