The word "fall" is a euphemism for "die." Here the word "sword" is a metonym for soldiers who kill people with swords. Alternate translation: "Soldiers will kill all his refugees ... armies" (See: [[rc://en/ta/man/jit/figs-metonymy]])
This can be stated in active form. Alternate translation: "the ones who remain alive will flee in every direction" or "the enemy soldiers will scatter in every directions the ones who remain alive" (See: [[rc://en/ta/man/jit/figs-activepassive]])
When Yahweh says that people will know that he is Yahweh, he is implying that they will know that he is the one true God who has supreme authority and power. See how you translated this in [Ezekiel 6:7](../06/07.md). Alternate translation: "understand that I am Yahweh, the one true God" or "realize that I, Yahweh, have supreme power and authority" (See: [[rc://en/ta/man/jit/figs-explicit]])