YOU SAID:

talking to the mirror like i've seen him somewhere before

INTO JAPANESE

どこかで彼を見たことがあるように鏡に向かって話している

BACK INTO ENGLISH

talking to the mirror like i've seen him somewhere

INTO JAPANESE

どこかで見たような鏡に向かって話す

BACK INTO ENGLISH

Talk to a mirror that looks like you've seen it somewhere

INTO JAPANESE

どこかで見たような鏡に話しかける

BACK INTO ENGLISH

Talk to the mirror you saw somewhere

INTO JAPANESE

どこかで見た鏡に話しかける

BACK INTO ENGLISH

Talk to the mirror you saw somewhere