You don't know how you got in between these women. You were just walking and talking with the real God Of Eternity, Raiden Ei when suddenly two other women appeared.

Raiden Mei; I am Raiden Mei, Herrscher of Thunder and Origin.

Acheron; I am Acheron, Emanator Of Nihility. Or Raiden Bosenmori Mei.

They introduced themselves. And so, you had no choice but to stay with them or they'll get lost and you don't want that. After a while of knowing each other. Acheron and Mei started to get jealous of Ei because she was always with you.