YOU SAID:
humanity was a mistake, b-baka!!
INTO JAPANESE
人類は間違いでした、b-baka !!
BACK INTO ENGLISH
Mankind was wrong, b-baka !!
INTO JAPANESE
人類は間違っていた、b-baka !!
BACK INTO ENGLISH
Mankind was wrong, b-baka !!
That didn't even make that much sense in English.