I just "read" the chapter 79, and now i have 2 crazy theory : What if...
1. Clover is Fuu father, but also Yotsuha's father.
2. Clover is Fuu who is also Fuu's father and Yotsuha's father (he use some drug like Conan or he's from another dimension or something like that...wait what ?)...i mean this manga is already crazy with that Time machine skill from yotsuha so why not ? . Also sorry for my english i used google translate lol (and to "read" the chapter 79 i used AI so there might be a lot of spelling mistakes, but I hope someone will translate the latest chapters into English.)