Well, that's a LARGE investment of MP. It's 21 to do that, which you don't get automatically -- at 20th you'd need to have taken Extra Morph at least once to pull it off. You also wouldn't get any damage increases from morphic weapons unless you take more feats, and pounce alone would take 2 more feats. So if someone put that much of a feat investment in, at 20th level, I'd be okay with that -- you're supposed to be awesome at 20th level.
Now, you can still get a lot of attacks at a lower MP investment -- you can get 13 attacks for 13 MP, for example, starting at 18th level when you get morphic flurry.
I dunno... is this overpowered? As long as you're not ubercharging? It's powerful, for sure, but it's still mundane...
