HAHAHAHAHA holly shit did Baku sat on top of his handkerchief? oh man, that's next level plays.
Anyway i need a resume on Eko.
As i understood, she was in love with Tatsuki and got the idea that her son Souichi would be the cause of Tatsuki getting an early end, so she elaborated a plan to get a free abortion, with the perfect excuse of it being an accident caused by other people, in order to alter destiny (which she also believes can't be changed), by killing her son Tatsuki would have a longer life, and her plan failed, Souichi survived and so she admits defeat.
Not the greatest mother nor lover.
Her plan involved claiming that she was able to change people, within a system in which some destinies were also unable to change, the people with unchangeable destinies would lose their money to her and get nothing in return other than the bleak news of their destiny being shitty and unchanging, which of course made those people develop deep grudges against her. The people with a grudge would attempt to kill her, fail and end killing her unborn son instead, since it would take place on camera she would have the evidence to say that the whole event was all on the people who attacked her, and that she was just a victim, getting rid of any responsibility for the miscarriage.
But her plan failed, she was the one who died, and Souichi survived.
Again not the greatest mother. Neither the greatest gambler, nor the greatest prophet.
Later on Souichi would watch the video of her mom's crazy plan and rambling, and learns about echolocation which would inspire him to learn how to do it, and he also gets the idea that his fate is set in stone for greatness, after all not even his mother could alter it (and her whole business model was to use casualty to change the future, future which she allegedly could see), which also feeds into his complex of trying to be perfect, after all now he has to live up to his destiny of greatness.
So did Tatsuki knew that Eko was planning all that, and just let her go with it? He does call her a bad woman, but the fact that he let her do it means he wasn't any better than her.
Also do you guys think that deepdown Souichi himself also belives on destiny being able to change, or did he eat up his mothers hypothesis and completely belies that he can perfectly predict the unchanging future? but of course with better accuracy than his mother who clearly failed her plan.