On its face it had been straightforward. Robin was dangerous now, she needed to be hunted. Somehow when he started pursuing her, pursuing her past, it all became much murkier. It was clear that she was somehow tied to Zaizen's past through Toudou and it was just as clear that her powers had taken a terrifying turn.
Why, then was he still hesitating? Why did each new piece of evidence seem to muddy the waters still further?
The only thing he could see with any clarity was that he was going to have to face her, it was the only way he'd know the truth. It wasn't what he'd set out to do, but it was, or would be, the inevitable conclusion.