There are certan limitations to Hoshi no Tama. First is the limitation of all Akashogan special tehcniques: If used too much, they will cause a pain in the eye, and bleeding, if continued to use even further. Secondly, Hoshi no Tama is unable to revert death; it can repair the body, but it cannot return the soul to the body. The third limitation is that the longer in the past the state that the target is reverted to is, the longer Hoshi no Tama will take to revert it and the more chakra it will take to complete the reversion.