The world was born of friction. The deity burned and broke, splitting into pieces of world, along with a few Jacks. Every Jack went along messing up his world. But there was an other Jack, one that none of the Jacks wished to talk about, because talking about him would mean becoming him.
The other Jack wielded the true power of the deity, that of fragmentation. Infected with the other Jack, every Jack would start to lose integrity and bastardy.
A Jack always presented himself to the world as the epitome of everything that had ever gone right. The other Jack poked at the picture till it collapsed. His hair was darker and a little more greasy. He made people lose faith in the Jack.
Nobody knows the goal of the other Jack, including he himself. A Jack spy who managed to talk to him communicated that he did it for fun. But really, what kind of excuse was that?