I wanted the ability to be reusable, so I chose a negligible casting cost and paired it with a high activation cost. I didn’t set it that higher, though, because I compensated by making it quite frail. You would probably get at most one use out of this before being killed, since you are probably casting it in a dedicated deck and sort of abusing it.
Blue is the color of messing with tapping and face-down, so that was a no-brainer.
Templating is probably not right; I tried changing it to “Choose one – Target permanent spell enters the battlefield tapped, or target permanent spell etc” — I think that’s how it would be written in real MtG. But it became too wordy and ofuscated the joke. So I let this one slide too.