YOU SAID:
I had a mind to treat him in such a way.
INTO JAPANESE
私は彼をそのように扱うつもりだった。
BACK INTO ENGLISH
I was going to treat him like that.
INTO JAPANESE
私は彼をそのように扱うつもりでした。
BACK INTO ENGLISH
I was going to treat him like that.
That didn't even make that much sense in English.