You've killed us both

[Renegade_]

Not really. We don't know what happened to the Daniel later. I bet the Shadow took him as well.

That's a bit of a stretch, since not only does the ending imply the opposite, but in all endings The Shadow comes in force, and does not waste time. So for it to curiously ignore the victim it's been chasing at length is seemingly a contradiction. "Hey Alexander, surprise, you die now! Yo Daniel, I'mma let you finish, BBL kthx bye. - The Shadow"

I had thought that since blood sacrifices of hapless innocents kept the Shadow at bay,

Spoiler below!

the destruction of Alexander sufficed to shield Daniel from the Shadow for the rest of his mortal days.

I considered it at first, but quickly realized it won't do since i) there were many sacrifices in the wake of The Shadow, and none of them sufficed. ii) Plus Alexander (and later revealed to Daniel) that the whole sacrifice motif to save his life was merely a false pretense constructed by Alexander to get Daniel to do his dirty work for him. iii) in another ending note The Shadow takes both lives, thus the sacrifice theory doesn't work.