You talked about how his muscles ached for too long. It would have been okay if you had introduced new ideas, but it was the same idea: that his muscles were sore and achy. I do not like the blatant rip-off of Highlander, because you don't make it your own at all - you barely spend any time introducing "the Game," assuming that we all know what it is, practically shouting to everyone that it is not an original idea. It's almost mentioned like an afterthought, like saying "You should know this, but here's a quick recap anyway."

Why does Maive want Charles? You don't explain this, merely passing it off as "She really, really, REALLY wanted him - but he was asexual, so he didn't. But Jack did. But she didn't want him, so he had his way with everyone else." It's cheesy and contrived. Your "Chaste Hero" annoys me, because there's no reason for why he acts this way. Explain it to us.

Which Doctor is this? I can't tell. Anyway, good chapter - though I wish there were more. I look forward to the next!

How mysterious! I wonder what her angle is. Clearly she, too, is an immortal; and, clearly, immortals can sense other immortals nearby. Also: what about the buzz in their heads? It did not seem to worry Charles and Jack much.

The end seemed a bit deus ex machina to me. What caused him to regenerate?

I've read this before -- well, at least the middle paragraph. There were several grammar problems and silly mistakes of that sort, mostly in the big paragraph around the middle.

Content-wise, assuming that the girl in the box is Virvel, why would she stay behind? I know that you have artistic license -- and that it is your story -- but she would never stay back and survive while we all die, in my opinion. Now, onward to chapter two!