I've got a JCV in my upcoming game. I went along the line of "since they're even more mysterious and secretive than the WCV, they're probably weaker"
I stole from the WW VampOfEast idea of reanimated Hungry Dead. Same back story: died, went to a chinese hell, came back, reanimated the body. 
These vamps feed on Chi as breath (suck the life breath out of somebody). Their powers run mainly on the sneaky-creep line. 
The template for the JCV is below
cost   abillity
- 1      vampirism  -  soul vampire  -  feeds on breath/chi
+0      Human form
- 2      breath weapon  -  sleep
+1      feeding dependency
             (powers deriving from it below)
- 1      cloak of shadows
- 2      inhuman recovery 
+2      The Catch  (vulnerable to "holy stuff" and Asian Folklore)
- 1      spider walk
- 3      spirit form
total is -7 refresh to be a JCV.
They're not stronger, faster, or tougher than a normal human, but do recover better and can become ghostlike. 
I told my player that cities with a JCV presence generally have a higher SIDS and hospice death rate, since newborns and infirm elderly are easier targets (hospitals and nursing homes have little in the way of Thresholds).