User blog comment:Kenpachi Yachiru/Unohana and Zaraki/@comment-6088207-20130124015301/@comment-6007998-20130125215559

1. Unohana may have been an original Gotei 13 member but who knows how long her and yama were around before the original gotei 13 got founded. He could still be a lot older.

2. Same as Xilinoc

3. Same as Xilinoc

4. As already stated she still is the most diabolical criminal in soul society history so they would never make someone like that head captain even though she turned over a new leaf.