This is a special kind of control deck, where you not only control what they play, but what they could possibly draw into. The way you do this is through you're typical counter spells (Censor), removal spells (Fatal Push), Board clears (Bontu's Last Reckoning) Discard mechanics (Dreamstealer), and mill (Ipnu Rivulet). And with a copy of Fraying Sanity out. Each time you put something in the graveyard, your opponent mills equal to what has been put into that player's graveyard already. So let's say you made you're opponent Discard a card, countered a card your opponent was gonna play, you wiped the board of 10 of his/her minions and made him mill 4 cards. So Fraying Sanity Will register that 16 cards have hit his graveyard, so that player would have to put the top 16 cards of his Library and put those cards into his/her graveyard. However what pushes Fraying Sanity over the edge is that they trigger separately. See when you have two Fraying Sanity's out on one opponent, lets use the last example again. So let's say you made you're opponent Discard a card, countered a card your opponent was gonna play, you wiped the board of 10 of his/her minions and made him mill 4 cards, now the first one will trigger causing 16 cards to go to the graveyard. Now the next one will trigger now not only will it register the 16 cards from before, but it will register the 16 from the first Fraying Sanity. So the second one will get rid of 32 cards, causing a total of 64 to be put into the graveyard just from this one turn. And three is even more crazy, four is kind of unnecessary and its becoming more and more of an expensive card as time goes by, so we are only running three. Some cool combos besides just 3 Fraying Sanity's + Ipnu Rivulet or something like that is Unsummon a creature when a copy of Dreamstealer is attacking, or my personal favorite is when they play a huge minion and you counter it while you have The Scarab God out and 4 mana open ()to not only exile the huge threat so no shenanigans happens and it comes back, but also you create a copy of it, sure its a 4/4, but if you hit something like one of the gods, or just something like a Scaled Behemoth, sure the stats might be not as good as it use to be, but its still a Zombie (Which is important for The Scarab God) with a important effect.
You are more than welcome to give me advice anything really to help me improve my decks that would be great so don't be shy to leave feedback. If you like the deck, let me know and hope you awesome guys/girls have a great day and may you draw well planeswalkers. :)