$re = '/^(.*)\.mkv\.mks/m';
$str = '[FAL]Eromanga_sensei-_-01(1280x720 Hi10P HDTV AAC)[70E7F984].mkv.mks
[FAL]Eromanga_sensei-_-02(1280x720 Hi10P HDTV AAC)[DE189E73].mkv.mks
[FAL]Eromanga_sensei-_-03(1280x720 Hi10P HDTV AAC)[A1E5B711].mkv.mks
[FAL]Eromanga_sensei-_-04(1280x720 Hi10P HDTV AAC)[F521AC93].mkv.mks
[FAL]Eromanga_sensei-_-05(1280x720 Hi10P HDTV AAC)[A776CE16].mkv.mks
[FAL]Eromanga_sensei-_-06(1280x720 Hi10P HDTV AAC)[24244951].mkv.mks
[FAL]Eromanga_sensei-_-07(1280x720 Hi10P HDTV AAC)[DFC32A09].mkv.mks
[FAL]Eromanga_sensei-_-08(1280x720 Hi10P HDTV AAC)[783BDB48].mkv.mks
[FAL]Eromanga_sensei-_-09(1280x720 Hi10P HDTV AAC)[677E4FE9].mkv.mks
[FAL]Eromanga_sensei-_-10(1280x720 Hi10P HDTV AAC)[89B519B2].mkv.mks
[FAL]Eromanga_sensei-_-11(1280x720 Hi10P HDTV AAC)[12B783EA].mkv.mks
[FAL]Eromanga_sensei-_-12(1280x720 Hi10P HDTV AAC)[56ABD770].mkv.mks';
$subst = "7z rn \"C:\\Users\\Matheus\\crunchyroll\\[FAL] Eromanga sensei (.mks).zip\" \"$1\.mkv.mks\" \"$1.mks\"";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php