Obvious spoilers to chapter 100. Just a few theories/thoughts I have. Please let me know what you think, and feel free to share yours!
OK, so. Chapter 100. The epic chapter of all chapters, leaving us with one very big cliff-hanger.
Bradley is obviously not dead. My guess? He goes through that pipe that most likely connects to Father's lair and joins in on the action.
Now to the actual deaths...
Fuu dying is acceptable. He was old, and more than willing to make the sacrifice. It is difficult, but I accept it.
Buccaneer dying is a tad more depressing. He was younger, and very strong-willed. He died smiling, however, willing to accept his fate, much like Fuu.
Riza, however, is the hardest of all for me to accept dying. She was introduced in Chapter 4, and her story and character has developed so much since. The only reason I say she is not dead, is because it has not yet been confirmed. Remember Marcoh? At the end of the chapter, The Bug's Bite, it seemed as though Marcoh had bit it (pun intended). Yet when the next chapter came out, he was still alive.
Here are my 3 reasons why I think Riza is still alive and my 1 reason to why she my not be:
Why she might be alive reason #1: We don't know how deep the cut is. It WAS a lot of blood, but the cut itself could not have hit any vital veins. She'd be at death's door, but not quite dead, in this case.
Why she might be alive reason #2: Going along with Reason 1's idea.... Mei's around the vicinity, yes? Although unlikely, while Roy is forced to open the gate after seeing Riza's wound, Mei and the chimeras could arrive and Mei could perform a little Retanjutsu and Riza would stop bleeding. She could at least live until she saw a doctor, then. (This theory is less likely, though)
Why she might be alive reason #3: If the cut is indeed not vital, this theory is plausible. Dr. Goldtooth may just be toying with our beloved Colonel. He wants to scare him enough to get him to do what he wants. Also, the doc might be unsure whether Roy would be willing to cooperate if he actually did order the soldier to kill Riza. If he wants Roy to cooperate, it would be much easier to do so with a live hostage. Basically; we'll save her life, but only if you open the gate. That sort of thing.
Why she might be dead reason #1: The oppostie of why she might be alive reason #3, pretty much. Dr. Goldtooth wants Roy to do what he wants. So, seeing through his gruesome eyes, killing Riza would be just the trick to get him to open the gate. We've already seen Roy act rashly out of vengeance... who knows what he'd do if Riza died? With all the right materials at ready, he probably would try to ressurect her.
So... following up on that... if Roy opens the gate to save Riza... what would happen? What would he lose after going through the gate?
But now back to the 4 main sacrifices; Hohenheim, Izumi, Ed, and Al. Hohenheim has been swallowed. Izumi and Ed are conscious. Al, on the other hand, is not. I'm thinking he's having another moment again, with his physical body pulling his soul. Maybe it's jsut me, but I have a feeling we'll be seeing Al's body in these next few chapters.
Ling will most likely be able to defend the door. But I'm not really sure what will happen with him.
And that's all I can think of. Be sure to comment and tell me your theories/thoughts too!