Hello.
So because you are running Black and specifically mentioned Graveyard hate, I think you should add
Deathrite Shaman. It is a great card in all stages of the game with three wonderful and cheep abilities. I think you should absolutely add it.
Another card that seems nice is
Shaman of the Pack. It's not a huge mana investment, and depending on the number of Elves you have, can do some serious damage.
Glimpse of Nature excellent in this deck. Being able to draw a card every time you play a creature (with all that mana, it shouldn't be hard) is amazing.
Green Sun's Zenith is another amazing card. With most Elves costing little mana, the ability to find an Elf can putting in on the board is fantastic.
These cards (especially
Glimpse of Nature) will be more costly than most of the cards in your deck, so that might be an issue. However, should you be able to afford them, I highly suggest playing them.