As wonderful as our deck is, sometimes it will have to be adjusted to deal with specific threats. While these cards may be less synergistic than the main deck, they all have very distinct purposes.
Tormod's Crypt: This is your dirt-cheap graveyard hate. It costs to cast, to activate, and only hates on your opponent's graveyard, not your own, so it doesn't mess with your Lingering Souls, Reassembling Skeleton, or Rally the Ancestors. It has one job, and it does it relatively well without interrupting your normal gameplan.
Bone Splinters: It's very uncommon, but there are a few cases where you may need more creature removal. While this can't kill indestructables, and sacking as a cost is usually worse than the Morbid mechanic, this card can also be better than Tragic Slip if your opponent has ungodly huge creatures or if you can't find your sacrifice engines.
Duress: Get a look at your opponent's hand and see what's going on! Good at removing planeswalkers, enchantments, or artifacts before they become a problem, as well as slowing down combo decks.
Suture Priest: This creature is a fun addition against the two types of aggro decks we struggle with the most - go wide, and burn. The extra life you gain from all of your tokens helps to prevent burn from closing out the game too fast, or the creature at least eats a burn spell that was otherwise aimed at your face. Meanwhile, it kills tokens almost on its own, totally shutting down options that go wider than your own.
Banishing Light: This is our choice card for non-creature permanent hate. While some people may choose a card like Disenchant for this slot instead due to lower mana cost and instant speed, this option allows for more flexibility in our targets, and is a better tool for dealing with Chalice of the Void, since most of our cards have CMC
Lost Legacy: A surprisingly inexpensive card that is back-breaking against combo-based decks. If they have one or two cards that they need to go off without any alternatives, this is a game ender. Becomes more useful the longer you dragged out your last game, since it gives you a better idea what has to be pulled out. It's a proactive Surgical Extraction and a Nevermore that can't be removed. A shame it can't hit artifacts or lands, but most combos don't use those two card types exclusively, so just aim for the other pieces.