Random Generator gave me Strands of Night and Jayemdae Tome. Tome again? I don't know what to do about these duplicate reprints. For now, though, it will do. I could have made this a lot more complicated, but this seems like a nice simple ability, and I can't remember any other card in Magic doing it, so let's just making something simple for now...

Hmm, yes. Powerful, but impressively straightforward. The only analogue I can think of is Skeleton Shard, and that was specific to artifact creatures.

The activation cost may be a bit low; hard to say. I might prefer for safety, but see how it goes.

It is a little hard to say, but Skeleton Shard does a good job of showing that the ability isn't too broken when you can pay . I think is balanced, but then I fear it wouldn't be played.