From M:TG Archive, a library of Magic: The Gathering information

Black is the color of death, darkness, plague, madness, and greed (although not necessarily "evil.") Typical black creatures include zombies, undead, and necromancers. Within the game, black cards are best at killing opposing creatures; making your opponent discard cards in his hand; raising your own creatures from the dead; and giving you the option to trade your own life points for more powerful effects. Black's weaknesses include the fact that it cannot remove opposing artifacts or enchantments, and many of black's best cards can harm you if you are not careful.