Default hand-grip case for both landscape and portrait

Does anyone know a good, slim case for the Galaxy Note Pro 12.2 which has a hand-strap on the back that can be comfortably used in both landscape and portrait orientations? I think for that the strap would need to be attached diagonally.
As I am right-handed, I'd want to have the button on the right and hold the tablet in my left hand.
That means the strap should be on the read from the top-left to bottom right when looking at the turned-over tablet in landscape mode,
ie one end would be somewhere near the s-pen holder and the at the opposite corner?

Even better would be anything that had a way to vary the location/attachment of such a strap

A built-in simple rubber-keyboard (like on the MS tablet covers) would be nice. A way to use it as a stand in both orientations a must.