afaik, there are several of them (i.e. like 1-2 of each) and dropped in blue smurfs event. keep bumping, i presume will be hard to get them prior to MF VU.
Saw one in Tzepu's shop for about 22k. A powerful anyway. I picked up the good one that he had. Hope you have good mf skills to use. I am at lvl 25 hit/damage and even the good isnt maxed out yet.