"First Mission" CCFF7-R OST 04

This theme plays in the opening train scene during the battle with the Shinra... ...cough... "Wutai" soldiers.

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