( headcanon request -- Kakuzu learning the stolen techniques of Takigakure and manipulating the mask/giving them form. )
[/ Though Jiongu (Earth Grudge Fear) was not initially intended for the incorporation of masks into the technique, Kakuzu had been able to manipulate it for his own usage. The four beasts that he can create are not capable of having their own free will; they are merely the extension of Kakuzu's via chakra. Keeping them formed and working correctly takes an incredibly amount of precise chakra control, which took many years of practice to perfect. The threads are controlled in a similar manner.
Having to battle more than one enemy at once is dangerous, which is what had spurred the idea of creating his monsters in the first place. First attempts at controlling more than one or two hearts at a time were laughable at best, but he was quick to learn in order to survive. ]
