Do you remember the moment when Ichigo was told by Hollow Ichigo that he was Zangetsu? The moment when Ichigo had entered his inner world and wondered where Zangetsu had gone, the only person who had appeared was Hollow Ichigo, in front of him, stating that he was Zangetsu.
Hollow Ichigo had challenged Ichigo for the title of King within the Inner World. Fortunately Ichigo had won the battle as he thrust his Zanpakuto onto Hollow Ichigo which turned Hollow Ichigo’s body black and started to turn into ash. Hollow Ichigo had warned Ichigo that next time it would take a lot more than this to be King.
Hollow Ichigo had appeared once again before the battle with Aizen. It seemed as though Zangetsu and Hollow Ichigo had somehow joined together to create an ultimate form. Ichigo was there to ask Zangetsu for help in obtaining the Final Getsuga Tenshou Form, Ichigo was awarded this power after finding out that Zangetsu only wanted to protect Ichigo.
That was a little story about Zangetsu which I might have reminded you. These fantastic image were all drawn by one very talented artist with the name of IFrAgMenTIx, you can go and check his work out by clicking the link, like, comment and follow him!