[Shiroth]

Originally Posted by Effu

Spoiler for Rem:

I don't really understand why Rem has to die. I know that she kills W and L in order to save Misa, somehow, but Misa in not in direct danger from them, so why is this rule applying rather the usual rule "increase shinigami's lifespan by killing humans"?

If L was to carry out his plan, then the 13 day rule would appear to be a fake, meaning that all fingers would be pointed at Light & Misa. Rem killed L, so this plan couldn't work --- meaning that Rem saved Misa's life.