Originally Posted by nexusolus

When Ichigo fights his inner hollow his hollow states that he and zangetsu are one being but which ever one has more power is in control and that is who ichigo borrows power from, when zangetsu is in control ichigo's Getsuga Tensho is i light blue while when the inner hollow is in control it is a black red. The more ichigo uses the hollows power the closer he comes to being controled by it.