@Aenor He's too gentle and polite to hurt her feelings on purpose. It seems like he needs her to kill him while she's feeling good about it. I'm sure he hadn't realised this about himself when he cooked up this yandere plan for his assisted suicide project, but if he took an evening to analyse himself and everything that has happened with Kuro, he would understand it, no doubt. It's going to be considerably harder this way, that's for sure.
hmmm....I believe "meek" glasses yandere might be superior...therefore I'd say blonde (tsun?)yandere first, as else she wouldn't stand a chance to make an impact after introducing glasses. Give her her chapter to sparkle before being out-shined.