I'm looking to improve upon this deck.

I feel that Bloodline Keeper is a bit too slow, but when I get him out, he's a powerhouse.

I know Blood Artist is very powerful but I'm not sure if it belongs in this deck.

Thinking about adding:

Stromkirk Noble, Falkenrath Aristocrat, Griselbrand, Cavern of Souls

I know my sideboard is weak. Looking for some help!