Strong... yes, potentially stronger than vulture sparks (but thats not exactly a staple archetype at the moment).
At the same time, its also nearly as hard to set up...
The main benefit here is that the king is pretty tough, as opposed to the vultures, which are very weak and prone to CC.
This means that the combo is slightly easier to set up since you may be able to play the king safely before unloading the fractal combo.
The PU / TU spam component will be no stronger here than it would with electric-vultures.
... Actually, I would probably prefer to use vultures in favor of PU / TU. They can be unloaded on the same turn as the main combo and would cost half as much as the TU / PU for nearly the same damage throughput.
Given the difficulties assosciated in set up and combo size, I don't think this is in danger of being too OP. Electric-vultures isn't exactly dominating the EtG meta right now as far as I can tell.
I think a more likely role for this card is in support of boneyard based decks. It would definitely be a great addition to the cat + boneyard archetypes.
The stable and continuous supply of skeletons will probably yield better long term output than the instant burst attained from fractal strategies. And with much smaller quanta requirements.
Continuous stream tactics also seem to synnergy very well with bonewall.
Moreover, one key difficulty in bone-cats is that once your field fills, your damage ramp maxs out. I know my favorite trick against the elder that uses bone cats is to pop out a shield and the skelly lock their field.
With this, the skelly lock wont be as much of an issue.
