I told you the Hoygukou was Sentient. I said it back in like Chapter 397, that it would end up being Sentient.
Here are those predictions again:
Aizen Plotline:
[i]Whoever didn't show up against Yammi will show up here. They will fight Aizen, and get beaten down, leaving Ichigo on his Own. [/i] If Yourichi and Ryuken show up to fight Yammi, this will be true.
[u]At least 1 member of the Court Guard Squad will appear, having realized the Severity of this Threat. One Member will engage in battle with Gin, who is revealed to be far stronger then Tousen was, HOWEVER, the Court Guards will reveal absolutely Insane Strength and the one member will Crush Gin like he was a fly against a Newspaper. The remaining members will attack Aizen, who will reveal his Bankai and Pwn Ass.[/u] This one will probably end up being wrong, considering how's the last few chapters have gone.
[b]Ichigo's determination to not lose impresses the Hyogoku, which is revealed to be Sentient and willing to pick it's master. It picks Ichigo, and with the new Power gained from it, Ichigo beats down Aizen. [/b] The Hyogoku being sentient is revealed, nothing else here has been completely proven or disproven.
Hollow Ichigo uses the power of the Hyogoku to form his own Body, possibly taking control of Aizen, and engages Ichigo in a battle to the Death, which Ichigo eventually wins.
Casualties and severe Injuries: Soi Fon will lose an Arm, as it will be 'too far gone to fix', Yammamoto will be Dead, as will Kyoraku and Jushiro, or at least mortally Wounded. Hiyori will die, and Hachigan will be unable to recover his hand. Hitsugaya will be completely healed, as will Momo.
As for Shinzo:
The problem with Gin's Bankai is that it doesn't have much Striking power. It cut through a few buildings, sure, but that's average in Bleach now a days. I'd say it's striking power is probably lower then his Shikai, so even if he could hit someone, as he has clearly done with Ichigo, he would have to hit them a ton of times to inflict even minor damage.