When Ichigo underwent his initial training to become a Soul Reaper, preparing himself for the seemingly suicidal rescue of one-time, full fledged Soul Reaper, Rukia, he had to face the devil...or should I say, the Hollow...within.  You're a Bleach Fan.  You know what a Hollow is and how it's created.  You know that Ichigo nearly became one; that he successfully ceased the act of possession. We find out later, of course, that his victory of the spirit wasn't so...complete.  When Ichigo has absolutely reached his limitations, the essence of the Hollow returns and Ichigo's ego is supplanted by a darker passenger.  When this Hollow personification emerges, there is no mercy.  There is no morality.  What there IS, thankfully, is a black, 100% Cotton t-shirt based on the hit Manga and Anime series, Bleach, featuring an image of a Hollow-possessed Ichigo.  Yeah, when the sword goes from humungous and white to tiny and black, it's time to get off the train.