Which is the bigger plot-twist? Finding someone you think died alive, or vice-versa?
Finding someone who you thought was dead to be alive is better in my opinion. But it depends
Finding someone who died alive it makes things happier :/)
I think the first one, because you already believe it's impossible to meet them anymore, but you always, subliminally, know that you may someday find them dead.But maybe all that depends on the whole plot.
I find the second one better. It's always surprising to have a main character die.