Warning: contains spoilers for chapter 70 of Boruto
Despite his importance to nearly every major story arc in Boruto, Amado still remains the biggest mystery of the series. However, his biggest secret, namely the death of his daughter and its significance to his motive, is becoming increasingly clear. She's somehow linked to one of his Kara "creations".
While Amado was never mentioned in Naruto, his knowledge and understanding of the shinobi world clearly mean he was present, at least during the last stages of the original series. In fact, it's his knowledge that makes him such an important character. He has an uncannily deep grasp of the Otsutsuki Clan, including its origins, goals, and methods of operation. He also has preternatural skills in science and technology, especially in ninja tech. As a result of Amado, Boruto's ninja tech is so advanced even Iron Man would be jealous. Even more interesting than his intelligence, is what is motivating his actions which seem deeply personally but unclear as to whether they are for good, for evil, or for something else entirely.
One of the leading fan theories suggests that Amado's motivations are somehow related to his daughter, who died 12 years prior to the beginning of Boruto. Many adherents to this theory have suggested that Eida, the super-powered cyborg he created for Kara is actually a reincarnated version of his daughter. Eida being Amado's daughter in Boruto is a plausible theory on a number of levels. Besides the fact that he seems to have a special affection, there is also the fact that Amado is not affected by her "powers of attraction" which can only be blocked by blood relatives or Otsutsuki's. Eida's power in Boruto actually makes the Sharingan look weak. However, there's one theory even more plausible. Eida is not the reincarnation of Amado's daughter, but rather Kawaki is.
Like Eida, Amado seems to have a special affection for Kawaki, but based on the story points surrounding their relationship, his affection seemed connected to his desire to eliminate Kara leader Isshiki Otsutsuki. Then after defecting to Konoha, his affection for Kawaki seemed linked to using him as a tool or weapon for whatever his ultimate goal was. While he was shocked to see Eida return, he did not seem very worried that she might be harmed by those who came to his rescue. Indeed, he had previously thought she was dead. But as revealed in Boruto #70 Amado's concern for Kawaki is much deeper than appeared at first, and more heartfelt than his reaction to seeing Eida. For the entirety of the series, Amado has rarely shown emotion. However, when he learned that Kawaki was on his way, he becomes visibly shaken. He actually seems scared for Kawaki's life. This is the first time readers see Amado actually concerned for the well-being of someone else.
The obvious reason for his concern is that Kawaki is someone special to him. He's not important in the sense of Amado needs him for this plan. Amado infamously reversed the death of Naruto's Jiraiya to create Koji Kashin. needed Koji Kashin to defeat Isshiki but abandoned him without much care at the most crucial time. Amado does seem to have a link with Eida but how special could that be if he believed that she was to be killed and did nothing to stop it. The only other person Amado showed a similar concern for was when he spoke briefly of his daughter. So why else would Amado show such concern for Boruto's Kawaki, if he is not somehow linked to his daughter?
The latest chapter of Boruto is available now in English on Viz Media's Shonen Jump App.