Armors is a cool project for many people. Many nations have used in the past. War may not be something good but it will be a good costume.
Armors are used a lot in the history. All of the empires have used an armor in history and its been very useful for all of them. They may look cool and you can use it as a costume.
Usually an armor is made up of metal. It is made up by curving the metal and giving the shape of your body. you will need many materials.
This relates to engineering by keeping track of what you do and using metals to build up something. Wear your armor and have fun!