[Arknights OST] bat bbrain

Extracted and edited from in-game file, all copyrights goes to HyperGryph. Note: this is NOT the original files in the game, NOR released by HyperGryph officially. download link for all soundtracks (including unreleased ones) : For soundtracks that are not released on EN server of the game (released on CN server before), you can find it there: (WARNING: SPOILERS ALERT)