Anchors
Lex gulped as he eyed the book with intense greed. This was not the kind of greed that one could shrug off, and Lex had felt it only once before when he encountered the Bangle of Narn - a bangle which had an entire galaxy within, with all of its resources available to any who wore it.
Back then, accepting the bangle would have put Lex at great risk, which caused him to hesitate in accepting it. Yet now, there weren't any risks.
But the feeling did not last long for the system, quite unprompted, provided him with a clear explanation of how the last anchor worked.
Basically, anyone who had a soul anchor in this book could find a way to continue living, even if someone murdered their body!