User blog comment:Kouseki/Arrancar=Vizard/@comment-1590714-20091214175202

Vizards may have a second form (eg if they die, they let their Hollow take over, regenerate and kill the opponent, or Resurrecion (Tosen)) and even though they are quite similar, it wouldn't be good for the plot if they had the same powers. Would be boring. To answer the question from my perspective: They are almost the same. I see it as a triangle - at one point, there is the Shinigami. At another the Hollow. At the last point, there is the Human. The more they gain powers leaning towards the other species, the more they change towards that point. And, at a certain point in time, they become Hybrids, and get the powers of both races. (perfect hybrid) However, so far, only incomplete hybrids have been seen, with the possible exception of Tosen, who seems to be able to use resurrecion.