In many stories I've come across a character dies only to be brought back to life through the power of plot convenience. Some of these that come to mind are Harry Potter and Krilin from Dragonball (Only know about that one because of my husband). I have to admit I've been known to do this myself. The story starts flowing, taking turns I didn't expect and before long my favorite character is dead (for me this is rarely the main character). I'll sit there staring at the screen my mind screaming "No! You can't kill them! They're the best character there is in this entire story!" But for some reason I can't delete that scene either, can't change it. That is the story my characters have told me, and so I end up getting creative and seeing if there is some logical way (can't stand it when stories break their own rules) that I can bring them back. This doesn't always work and many times I've had to set a story aside to deal with the fact that my favorite character is dead.
I find when I read stories where the character is brought back through Plot Convenience I just about am ready to throw the book. Seriously, if you don't want the character dead and can't provide a rational explanation of how they can come back (something I'm likely to believe) then just don't kill them off. A bit hypocritical perhaps, but there it is.