William staggered back to his feet, gasping for breath.

'What is...this? My body feels almost like a husk. Why do I feel like it's not my body?'

'Fushi Tensei, my technique of pseudomortality. We now hold the form of the great white snake, and this body is to be our host.'

William could feel the wave of snakes as though it were another part of his body, and attempted to move them. They responded, splitting around the personae and attempting to overrun the pit fiends with a wall of outstretched blades. The multitude which remain, make a rush for the gate, attempting to bring it down with the weight of their musculature.

'There's so much vital energy here...I never knew that I was so...weak. It feels like I could just walk through a wall with this strength.'

'It is not yet fully developed; we're only at around 10% of the capacity brought by this technique. That snake wave, properly known as the Formation of Ten-Thousand Snakes technique is probably at the absolute limit of our abilities for now.'

'Well, that's your first phase of integration. I believe that it was to be my turn next?'

'Right. First though, what will you be integrating, Aizen? I don't really want more surprises like that last one.'

'Very well...for my first three-hour phase, I'll mostly be integrating some of my spiritual pressure and a bit of my swordsmanship. It won't be anything drastic like Orochimaru's, but it will provide a strong base for later.'

'Very well, then. Now let's see if we can't help anyone here...that one looks good.'

William surveys the fight, then enters by attacking the pit fiend which is busy casting, first with a grouping of snakes emerging from beneath the sleeve of his robe, seeking to inject a paralyzing venom, and then with the Blade of Kusanagi, seeking out the eyes.