The sha are byproducts of the Old Gods and Emperor Shao Hao's emotions, but don't seem to necessarily obey or work for them, they just do whatever they want. The Sha seem to be to the Old Gods what the Saurok are to the Mogu.
Hence, since they're not actually aligned with the old gods (and as a result are hurting the mantid by pushing them too hard), the Mantid oppose them.
You are now future Jack Noir.
Presently, you are trapped in a single moment, which increasingly feels like an eternity. Your boredom is surpassed only by your all consuming rage and contempt for existence itself.