Reminds me a whole lot of my Sylph (http://elementscommunity.org/forum/index.php/topic,21608.0.html). A little too much...
Not at all, my friend. Not at all. Shadow Demon is intended to be used quite differently compared to your Sylph. Your creature is entirely intended to protect other creatures. Mine, however, can be used in a couple of offensive ways. First, there's the obvious use of cloaking itself and dealing high damage. Second, since the target cloaked by Shadow Demon is invisible to
both players, it is effectively a lobo for 3 turns. On the downside, you cannot hide your own creature without lobotomizing it for 3 turns. Our cards are similar, but very different at the same time.
For the upgraded version, decrease the cost by 1? Or should I decrease ability cost?