YOU SAID:
It would be extremely painful...for you.
INTO JAPANESE
あなたにとっては非常に痛いでしょう。
BACK INTO ENGLISH
It will be very painful for you.
INTO JAPANESE
それはあなたのために非常に痛いでしょう。
BACK INTO ENGLISH
It will be very painful for you.
That didn't even make that much sense in English.