YOU SAID:

then, everything changed when the fire nation attacked

INTO JAPANESE

その後、火の国が攻撃されたとき、すべてが変わった

BACK INTO ENGLISH

Then, when the country of fire was attacked, everything changed

INTO JAPANESE

その後、火の国が攻撃されたとき、すべてが変わりました

BACK INTO ENGLISH

Then, when the country of fire was attacked, everything changed