The early attempts varied widely between way too strong and way too weak, but no that they have learned not to make these designs to fancy, these cards have become a basic component of blacks abilities
While I'm not a huge fan of cards showing up just because they're good, Hullbreaker HorrorHullbreaker Horror is going to give you lots of value for doing what the deck is trying to do, pester your opponents and distract from your tiny pokes along the way
Proliferate adds counters
The most problematic and difficult to deal with permanents in a game of Limited are frequently large fliers like Twinflame Tyrant, terrifying equipment like Celestial Armor or Leyline Axe, or enchantments like Valkyrie's Call, and Vivien's -3 ability does a great job at dealing with these threats in a hurry
With legendary creatures like Emrakul, the Aeons Torn and Ulamog, the Infinite Gyre at your command, your opponents will tremble
Whenever Ojer Kaslem deals combat damage to a player, reveal that many cards from the top of your library