It's better now, but not quite. Right now it does two things though besides damage:power reduction and shade generation. Three if you count the shade's vampire ability. Most weapons do only one thing besides damage. Let's assume you have Nightfall out, since that is the obvious synergy. Each turn you
1) Do 5 damage
2) reduce a creature's attack by THREE.
3) Generate a 4/1 creature.
4) Heal 4 damage (vampire)
This is a bit much when put all together. The power reduction ability is on par with sniper, as it can take over half of the creatures out of the offensive picture in one shot, and most of the rest in two. And short of rewind, there is no way to heal power loss. In addition, it generates creatures about on par with fireflies which heal you.
So basically you have a vampire firefly queen with a (sorta) sniper ability that does good damage as well. I would only keep two of these, and either remove the others or nerf them to oblivion. Personally, I would have it do low (2) damage, drain 1 or 2 attack, and generate a non-vampire shade.