What is Shia opinion on Armageddon? It is commonly believed that before the end of world a big war will happen between good and evil in which 99 out of 100 will die. Some reference to Sunni books quoting malaham Al kubra. Do we have any Shia references to it? Will it happen before Imam e zamana or after his blessed zahoor?

We believe that when Imam Mahdi (atf) reappears he will fight the forces of evil and injustice and many will die. This may be what you’re referencing