YOU SAID:
yay humanity's failure
INTO JAPANESE
イェー人類の失敗
BACK INTO ENGLISH
Ye humanity's failure
INTO JAPANESE
あなたがたは人類の失敗
BACK INTO ENGLISH
You are the failure of mankind
INTO JAPANESE
あなたは人類の失敗です
BACK INTO ENGLISH
You are the failure of mankind
That didn't even make that much sense in English.