sentences:  Terra, Aqua, and Ventus reunite at the Keyblade Graveyard, where Xehanort and Vanitas reveal their plan to use the χ-blade to unlock Kingdom Hearts and start a Keyblade War, an apocalyptic event that nearly destroyed the world in the past.Terra's heart is swallowed by darkness in the ensuing battle, and Xehanort takes over his body to replace his own aging one.However, Terra's mind remains within his discarded suit of armor, which comes to life and defeats Xehanort.