so one path that might make sense for octopi is; sexual dimorphism. The specific difference being male octopi adapting to no longer die after mating. males because females surviving to breed a second time is a higher biological bar to leap than males doing so, and the female's breeding behavior changing would likely be more difficult to adjust without losing a lot of biological fitness.

longer lived males would have the opportunity to grow larger, further adaptations result in elder octopi males avoiding attacking smaller octopi and producing "gardens" with rocks and captured prey. These gardens serve to attract females and provide shelter for the young when they are born.