YOU SAID:
Vengeance will be mine!
INTO JAPANESE
復讐は私がやる!
BACK INTO ENGLISH
I will take revenge!
INTO JAPANESE
復讐してやる!
BACK INTO ENGLISH
I'll take revenge!
INTO JAPANESE
復讐してやる!
BACK INTO ENGLISH
I'll take revenge!
That didn't even make that much sense in English.