On appearance alone, is it mei or does Acheron look nothing like Mei?

for me HI3 Mei looks the best

they all look the same but with different hair styles and chokers

hah, I think you forgot APHO Mei from Honkai Impact 3rd

IMO, Acheron just looks a bit older. Granted this could be the perspective differences between the images.

GEOMETRY DASH FOUND

acheron is mei but doesnt know the way to kitchen

Acheron real name

can someone tell what honkai gauken is?

trio honkai can solo genshin using 1 slash

So... Yeah if you go and check the leaks on unreleased characters there is literally a file on Mei. The concept art of the scrapped "Mei" is also almost 1 to 1 with acheron so yeah she is Mei of Starrail.