Slayer and Charlie have nothing in common though. Slayer's only niche is her 9 power, with her ability, she has 7 gapping potential, but she isn't a card you can just throw away as a bluff DR like you can with Charlie.
Ielena is garbage, big duh there, it doesn't make Dragomir that good though. The issue with Dragomir is he's not that good in half decks, since running into Gheist or Roots turns him into a fat 5 stared 9/4, so he doesn't do that well when he's split 1-3 with the other clan.
And then you run into the problem of Mono Nightmare not really being very good outside of a few modes.