Each age has its own apocalypse warrior. Ramayana had Lord Rama. Mahabharata had Lord Krishna. And Lord Kalki is said to be apocalypse warrior of this age.
There is always good vs. evil battle going on subtle dimensions. And the forces of good take human form to take the world to justice, and love.
Kalki is said to riding on a horse carrying a sword. The seven immortals of Hinduism is said to assist in this final battle of apocalypse. Ramayana was fought near Sri Lanka. Mahabharata was fought in Kurushetra. And this final battle of thing age will be fought some place in this earth. And the society will be remodeled and values of humanity will be re- sown.
The world has advanced scientific weapons now and the coming of this final apocalypse hero might be just a symbolism. The use of sword in such battle might be just a symbol of similar Hindu deities. Will the third world war start once with the coming of Kalki? It’s unknown but there are prophecies that Kalki , the last apocalypse hero of this age will come to save the humanity from evil and take the world to justice, righteousness and love.