We learn in part 2 that Quincies have a physiological intolerance to Hollows, so why didn't the Visoreds use Hollowfication ...

The Visoreds were former captains and lieutenants of the Soul Society. Let's see which among them is the strongest.

One of the best aspects of Bleach is its Bankai, a part of the power system which upgrades the user's sword. Bankai has many shapes and sizes, ranging from useless abilities to overpowered attacks.