8 Things We Missed In The Assassins Creed Shadows Trailer 

Yasuke wasn't entirely a slave when he came to Japan. Prior to coming to Japan, he was already trained in combat, and served as a bodyguard to the Italian Jesuits that took him under their care (those guys in red you saw bowing alongside Yasuke). He did some mercenary work in India, then the Jesuits wanted to spread Christianity in Japan. They knew that Nobunaga loved all things Western and unique, so they presented Yasuke. Nobunaga didn't know Africans existed, and after realising that his skin was real, and (after the Jesuits bragged about his strength) Nobunaga tested Yasuke against reportedly 10 of his best Sumo-wrestlers. After that, Nobunaga formally employed Yasuke as a retainer, which wasn't a ward, but a swordbearer. See, in the West, it might not be an important task, but in Japan, it was a very high honour. After all, Nobunaga himself was the Sandal-bearer to the previous Daimyo. Yasuke, due to his strength and towering height, was also made Nobunaga's personal bodyguard, and he was even part of his inner social circle, an honour not even many Samurai were treated to. Whether he was made Samurai or not is a difficult question, because there is a lot of evidence to suggest he was made one, but not enough to 100% conclude it (such as the fact that more than 90% of retainers were Samurai, however, Yasuke could have been part of the minority that wasn't one). So the true answer as to whether he was or was not a Samurai is "We don't know". Unrelated, there's another detail you missed in the trailer. Naoe performs a double Assassination on two guards using the combination of her Tanto and her Hidden Blade. This causes many people to assume that Double Assassinations will be making a return, and that most likely you need to equip the Tanto to do it.