"The Scars That Remain" CCFF7-R OST 28

This theme first plays when Sephiroth explains to Zack what happened to Genesis and laments about not being viable to be the donor for the infusion.

You can purchase Crisis Core Final Fantasy VII Reunion here: https://ffvii.square-enix-games.com/en-gb/games/crisis-core/#buy-now

As of the release of this video, no official soundtrack for Crisis Core Reunion has been released (to my knowledge). Buy the original Crisis Core soundtrack here: https://music.apple.com/us/album/crisis-core-final-fantasy-vii-original-soundtrack/266734037