You first. But this is a separate issue.
Why is death a prerequisite for a savior? It's easy, myths can be much more inspiring than real people, who can be disappointing.
Here's a fairly comprehensive one:http://www.bbc.co.uk/religion/religions/christianity/history/whokilledjesus_1.shtml
It is true that any death could sever as a catalyst for myth and lore, and I have not refuted that the death may very well have been necessary.