What is an idiom?

Destroy soldiers, destroy armour, tie, cast armour, defect and unload armour, accumulate Jia Shanqi, Zhang Jia, Li Yi, be sharp by armour, be blunt by armour, crown the world, be bruised all over, be pillowed by armour, be tied by armour, be squashed on the chest, be rolled up, abandon armour and defect, and crush armour.