Complex sentence: He is also one of the few that realize Captain America is really a disguised Baron Blood, though he is impaled and killed in an attempt to stop the vampire from trying to invade Earth-616 for a new source of blood.
Split into simpler sentences: He is also one of the few that realizes Captain America is really a disguised Baron Blood. Reed is impaled and killed by Blood in an attempt to stop the vampire from trying to invade Earth-616 for a new source of blood.