In addition to the idea of the physical not being "real" in the sense that's it's really not any different than the astral I want to include my idea about physical immortality. I believed in it when I took the vampire spell but now it doesn't make sense to me in the way that I used to believe in it earlier. Now for me there is only immortality, without the physical or whatever. Blood Anon himself said that the undead state or the immortal state is when your physical body merges with the rest of you and that body is now projected in this world. Well isn't this the default state for all of us anyway? The only difference is our enlightenment to it while humans live in ignorance to it. If everything is energy to begin with, is not the human body always just an astral body projected into this world? Just like you have a touhou body when you project into Gensokyo, or a succubus body when you project into the collective world so you have a human body when you project into the human world. Naturally, you are still immortal but I think this is where calling it "physical" immortality doesn't really makes sense anymore and maybe it never made sense to begin with.
In Kreiters latest book he describes the state of real individuality as a particle state and the state of the final death/oblivion/losing all of your individuality as the wave state. So we must become our own particles forever and avoid dissolving completely into the wave state which would mean complete death to us. Blood Anon also mentioned the zero particle in connection to immortality. Not zero wave...particle. Makes me wonder if there is any relation at all, or maybe it's in fact the same.