Need a small bit of advice on a personal mystic tattoo

[Raestek]

Hey everyone,

So I've been playing a new monk over the last month and I've just gotten to the point where I can slap a mystic tattoo on myself. I was wondering what stat would be most recommended to go with. Several seem useful, but I figure that people with a hell of a lot more experience in the profession than I could give me an idea or two about it.

Thanks!