It's a combination of two event trailer's for Arknights. The Under Tides PV and it's sequel event the Stultifera Navis PV. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-29GrA7y7wnY.html ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-SpoTaeHAtHQ.html
