User blog comment:B214/Volume 23 discussion blog/@comment-190.160.185.214-20170328173222/@comment-30924344-20170329142109

@Pawn Even if she might die (Issei's parents becoming devils could happen), none of the other mother-in-laws will ever match Mrs Hyoudou's "Mother's Protection". Also the actual current mother-in-laws are Venelana and Irina's mum and that's it. Your list is a future list with the exception of the 2 mum's I mentioned.