It's a dream within a dream. Ichigo was dreaming when he got stabbed and the vision of Kenpachi appeared giving him advice. Who or what Kenpachi represents, I don't know. But there are some who speculate that this could be Zangetsu trying to help. As for me, I dunno.
It's a long story. It all started one night when a dark haired girl in black garb appeared in my room. And well, to cut a long story short, my house was attacked by some weird creature and the girl got hurt protecting me. Then in order to help me stop the creature, called a "forum troll", the girl hit me with her "banhammer"  and I gained all her powers and my own banhammer. I used my new found powers to "ban" that forum troll. The rest, as they say, is history.
 

dun simply say