Just add an octave harmony at the beginning that sounds like the octave at the end start to ascend in volume at 0:12 and completely go silent at 0:23. (At 0:00-0:11, The octave wont play.) And thats it.
Is this what you wanted? I want to make sure I understand what you're asking for. ;p
https://drive.google.com/file/d/13Ta1MpGc_BwbWz9-toaf-zGcgEluqP9E/view?usp=shari...