It's a repeated point of the heaven's that the world is full of opposites; for example, the Forest Shadow and The Mother, and Chai Ka and Ya Zhen. Nearly everything in the game has an opposite, readily apparent or not; Sun Kin and Death's Hand, Dawn Star and Silk Fox, Mistress Vo and Jian the Iron Fist, Black Whilrwind and Henpecked Hou, Smiling Hawk and Master Radient etc. But who doesn't have an opposite? You, and that's why you can tip the odds in either direction.
Actually, you do. Three of them infact. Powered by some sort of outside evil even. Encountered when trying to come back from the dead in the Spirit Monk Temple. None the less, you beat the crap out of the evil yous though.
Maybe, or maybe it is Master li
Sun-Li says that the Spirit Monk's role is to oppose him before their final battle, which doesn't really leave who is the opposite of the Spirt Monk (or vice-versa) as ambiguous. Although, Li says that their opposition is the Celestial Bureaucracy trying to restore balance, which could mean that initially the Spirit Monk didn't have an opposite but ended up with the Glorious Strategist.
Now that you mention it, who's the Water Dragon's opposite?
Probably the ourside evil. since it seems to represent anti-life itself. or maybe someone who brings life
In Jade Empire, with the Water Dragon out of commission, no souls of the dead were passing into the afterlife. There was also talk of reincarnation with the Great Wheel. Given that none of the recent dead could pass through, rest, and be reborn, it was also just as likely that fewer and fewer children would be born, and the living would soon be overrun. Eventually, everyone would have been a trapped spirit, slowly going mad from the torment of being trapped.
Actually it can get better, but the problem is its (Closed Fist) likely to get much worse first. Its not just the prospect of eventually dying and having an after life filled with nothing but torment and madness to look forward to, its HIGHLY likely that unless the Big Bad was defeated and more importantly, the "Hero" wasn't a Jerk Ass, it could mean the a justified As God Am I situation in the same theme as Hades or Lucifer.
More to the point, the Jade Empire belief system and pantheon may be unique to itself and beyond its borders, there are more people that are unaffected by the Jade Empire's troubles and are ripe for the conquering.
Empowered with even MORE souls, this could mean that the Celestial Bureaucracy could be facing an INVASION from a former mortal, as no Souls/Spirits means the various heavens would weaken while the Big Bad just gets stronger.
And just to make it even worse, if the Water Dragon's power could be stolen, why not other Gods? Along with Powers and Portfolio.
The Water Dragon's powers were stolen because she had given some of her power to the monks, as well as created a medallion with similar properties. As long as the other gods don't do that, they should be fine.
The end result of having the Big Bad end up being an all powerfull Zeus figure (a God that rules after beating the old God) that can remake all of creation, and thus, allow life, light and happiness to return (as long as proper grovelling and offerings are regularly supplied) will probably just be a mark of a new epoch. As to whether or not the ends justifies the means, well, who can know the mind of a God? :P