Petrosius,
I would translate "everyone dies" in the singular "Omnis", since the word everyone is a singular noun, even though it has a plural connotation. "Omnes moriuntur" means "all die" which has a slight difference in connotation in the Latin at least.
So, I would say "Omnis moriatur".
Melas, That's pronouced "awhm-neece moh-ree-ah-toor"
Unusquisque moritur!
"Moriatur" is the subjuctive and would mean "let everyone die."
Except it wouldn't translate that way. Omnis means "all", not "every". So what you'd end up saying by writing it that way is, "All dies" (as in, all of a person, or all of some other particular living entity).