Truth Behind Ishida's new Potision

I believe Ishida is consider the last Quincy alive because he is young and still practice Quincy arts. Yhwach basically confirmed that all the VR members are spirits. I think the fact that the Dangai wasused as a penal colony 1,000 yrs ago, the VR army making there appearance and the legend of the emperor's resurrection are connected.

I was wondering if the VR Quincies are a mix of spirit people and living people mainly because we have seen that Quincies are still being born. But now that I think about it, Byakuya was born in the Soul Society from Shinigami parents. It is possible for spirit people to have children if they are powerful enough. Ichigo also has a Shinigami father.

It is very difficult to guess what Bach is up to. For some reason Bach is unable to leave the Shadow Realm for long. Maybe he is dying after all and needs a successor. Or maybe Bach has plans he wants to pursue on his own. I still think the most likely explanation is, he intends to use Uryuu for his own purposes as a figure head and cannon fodder in the coming battles. Especially if he gave Uryuu Yamamoto`s power, the impact of such an assault would have a huge impact on the morale of the Shinigami. 

Ryuuken is still alive. We haven't seen him in his Reishi armour yet. its been 999 yrs since Yhwach has returned. He needs 1 more year before he is at his prime again. I think since Uryru is from the Ishida clan and has potential to become as powerful as him. Yhwach may attempt to take over Ishida body by putting his soul into Ishida. On the outside he is Ishida but on the inside he is Yhwach.