THIS BODY IS READY

[Niale]

Its Reunion he is talking about probably. There are number of clones who are brainwashed with mako, and he wants too...
Well, he plans to be the bad guy and you fight him later on in Northern Cavern.
That's it, this game usually relies on memory idenity crisis.

He only uses the Reunion to complete JENOVA again. The body itself is for his purpose and when he does not need it any longer he gets rid of it to give it back to JENOVA again as he has a body for his main goal and that body was the bodyhe was born with.

You got it, that's the body you see in "Northern Cavern"
Bizarro?Sephiroth - The Final Fantasy Wiki has more Final Fantasy information than Cid could research
Safer?Sephiroth - The Final Fantasy Wiki has more Final Fantasy information than Cid could research