You get a full two turns to play these cards so the impulse effect is fairly lenient and because at the time of writing this card has been recently printed, it's very accessible too, much cheaper than the identical Reckless Impulse
We went through various versions, but here's what we handed off from vision design: Afraid (If an enchantment, Horror, or Nightmare you control entered the battlefield or attacked this turn, all opponents are afraid.) This version interacted not just with enchantments, but a few of the creatures we felt most embodied the genre, Horrors and Nightmares
But in a format like Legacy that's all about playing efficient threats and answers, it turns out that countering a one-drop for free is really goodso good that soon after the card was released, pretty much all blue decks were playing the card
4 Liesa, Shroud Of Dusk A Different Approach Say you're a bit tied with traditional Kindred-style decks and want to test your deck-building skills with something new
Because they have such a wide history in Magic, vampire commanders cover a lot of ground