Homura turns into a witch

In Homura’s final epiphany, Madoka steps on their twin chairs and takes the position of Christ in the cross (i.e. the god that made the ultimate self-sacrifice of taking the burden of everyone’s faults), only to fall comically and dissolve into nothing as a symbol of the uselessness of it all. At the sight of this, Homura fully realizes her own failure as her guardian, curses herself and falls into despair.