Stuff like Snuff Out or Dismember are already heavily played cards, but here, you get to draw a card from them because you lost 4 life, and you also get to drain your opponents for 2 life, offsetting your life loss
Similarly, a deck built around very expensive spells (such as Dragons or spells like Exsanguinate with in their mana cost) will likely play powerful, expensive ramp no matter the cost of its commander
City of Brass is a decent replacement for Glimmervoid if you cant find any or if you expect to play against a lot of removal and not a lot of aggressive decks, although I wouldnt recommend playing more than two
For just 1 mana, you may get a free swing and treasure token before your opponent has any removal spells or defenders
And unlike Sorin, she doesn't require a commitment to a single tribe, she's good in more builds