Past zodiac reincarnations

I just finished watching the anime after reading the manga a looong time ago and I wish there was more lore!! I really wonder how the past reincarnations of the zodiac spirits interacted. Were the past gods always spiteful or was Akito just a jerk because of her past abuse? Did the cat and rat automatically not get along the next reincarnation after the original? When did the “new” version of the zodiac story replace the OG version? I have so many questions!!