not all there (RWBY x Azur lane)

memories. memories that seem all too familiar yet foreign to them

Ruby remembers the sounds of cannons fire and the splashing ocean

Weiss remembers a feeling of a cold northern air and a deep feeling of loneliness

Blake hears the sound of explosions and getting injured

Yang remembers the buzzing and things flying things on the air dropping bombs from the sky

what are these memories? where are they from? and most importantly who are they?