Jinchurikki

If a tailed beast or other powerful creature has been sealed inside an individual they may gain access to its chakra and abilities, these hosts are referred to as Jinchurikki. If the Jinchurikki undergoes great emotional anguish or anger it can provoke the chakra of the beast to start undergoing a transformation into the beast, this typically only happens years after a seal has been used or if a seal was too weak to properly contain the creature.   When a jinchurikki begins transforming there will be visible signs. The first is the eyes of the jinchurikki will transform to become more like that of the tailed beast sealed inside of them along with other traits such as nails and teeth becoming larger and sharper.   Jinchurikki also gain access to any chakra nature, kekkei genkai or special abilities possessed by their beasts. There are also common abilities that all jinchurikki can gain access too.