>>49108648Probably a combination of Genshin and Honkai lore. Potential spoilers below.
Primogems in Genshin are the remnants of destroyed universes. In Honkai, there was a major character named Elysia who was basically a messianic figure. She sacrifices herself in the "previous era" of Honkai to save the world, essentially, and that sacrifice involves sealing herself away in ice. She's said to have made this sacrifice in every existing universe. March has a lot of personality traits that are similar to Elysia's, her design is similar to Elysia, she has amnesia, and she's found floating through space encased in "six-phased ice," which supposedly has a connection to the "Imaginary" element in the game. In the game lore, "Imaginary," relates to the Imaginary Tree, which is a metaphorical tree that connects all universes in the Honkaiverse. 