"Terrible Truth" CCFF7-R OST 13

This theme first plays during the cutscene when Sephiroth tells Zack that Angeal betrayed them.

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