Is there any novel that attempted something on the level of Tsubasa Reservoir Chronicle? Like Clone Syaoran x Clone Sakura give birth to Syaoran, Syaoran get cloned to create clone syaoran, syaoran meet sakura, get event where sakura is cloned to make clone sakura, clone syaoran reincarnated in the past with clone sakura to give birth to syaoran, repeat ad infinitum? (Sorry if there is a mistake). If not, any stable time loop story will do.
It's not a novel but a webcomic... I'm talking about homestuck. Yeah, pretty sure it fits what you are looking for. Spoiler
Not novel, but if you are ok with BL manga there's one with family tree so complex, it's only possible within ABO universe. Spoiler: picture related
Demi-Gods and Semi-Devils one of the MC fall in love with several woman and the woman started to fall in love with MC, but it turn out MC's father is a playboy when young all those woman is MC's sister including MC favorite girl. So MC run off. Then the big plot twist near the end of the novel it turn out MC's mother was fed-up with MC's father playboy tendency decided to have a one night affair with the boss of '4 Greatest Villain' which resulted in the birth of MC. So in end its OPEN SEASON for Girls because they are not related at all. (MC have around 6-7 Girls pursing him and MC father have equal number as well and most of them still loved MC father)
Old manga, Tsubasa reservoird chronicle is like looping world, Syaoran end became father of both Tsubasa and Kimihiro, to break free from this looping time syaoran and sakura paid the price. Not really complicated Maybe Mother of Learning,