ICHIGO FINAL ZANGETSU FORM!

[Agato]

Okay this is to answer nutters question and everyone elses...
That person ichigo was fighting to get his final form was zangetsu younger self.
proof-
http://i55.tinypic.com/27zdtmc.png

Ichigo never went to see zangetsu in his bankai form.

Now imo mugetsu could just be one of his attacks not what its gonna be called but I could be wrong.

EDIT:
I read a little bit more and he said he was Tensa Zangetsu but it basically is just the younger one