Discard is still a very popular deck format these days among the countless MTG players who exist solely to piss everyone else off.  There are a lot of discard archetypes out there, some that are more slow and controlling and others that lie on the more aggressive end of the spectrum.  If you favor the latter type, you might want to consider running a couple of these:

This card is pretty much useless outside of a specialized deck, but he’s the perfect fit if you’re looking to use a discard deck with a powerful creature base.  If you’re doing things right, you should be having your opponent discard at least 1 card a turn, and so in a perfect situation you’ll be swinging with a 4/4 fear on turn 4.  Of course, this guy can get bigger than that; cards like Hymn to Tourach and Blightning can double-pump him, and he combos insanely well with Mindslicer, provided you find a way to get the latter into your graveyard (this works because when your opponent discards their whole hand at once, they’re still discarding multiple cards, and so the Nocturnus will pump for each of them).  Another card to consider using would be Cunning Lethemancer; you’ll be guaranteed a discard most turns (excepting the ones where your opponent has no cards in hand; be careful not to get too carried away), which will ensure consistent pumping of your Nocturnus.

If you’re looking to add some oomph to your black control deck, this just might be the card for you.  Coupled with Megrim, this guy can be a game winner.  See you next time!