TL;DR: Yasuke is a very resounding "meh." It struggles in terms of story and character, it has trouble deciding what it wants to be, but it's utterly carried, in my opinion, by it's art and music.
Story: 3/10
Speaking solely on the historical elements, if that is what you are here for, you're gonna be disappointed. While Yasuke's backstory is accurate, the story itself is focused on an older Yasuke trying to protect a girl with magical powers (see my Character section). While I typically enjoy this kind of older, somewhat jaded male protagonist and young girl who is special in some way, it isn't done well here.
My issues with the story itself can be summarized as "The story tries to introduce too many characters for it's short episode count which causes the majority of them to become forgettable and the show struggles deciding what it wants to be." For the first, as an example, the story introduces four minor antagonists around the end of episode 1, all of which I couldn't give you more than a single thing I remember about them (with the exception of Haruto, the one actually decent minor antagonist in the series.) If you were to ask me what the remainder of them were, I would only be able to say Creepy Priest, Russian Lady, and "I literally don't remember a thing about them, they were an archer, I think?"
As for my second option, there's thankfully not as much to go through. The story has trouble deciding what it wants to be in places, an issue no more apparent in it's world. You have some historically accurate stuff, and then right next to it, magic and *giant mechs that were reverse-engineered from the Mongols*. The story can't decide if it wants to be a fictionalized period piece on late 16th century Japan and a historical figure who just dropped off the map after being captured or fantasy that just so happens to use anime versions of real-life historical figures, a la Fate. The story also creates a lot of deus ex machinas towards the end.
Art: 8/10
As expected from MAPPA, the art is very good. Not their best work by any means, but it is still very good.
Sound: 7/10
Speaking on the music, it's not what I expected them to go for, but that's not to say the music is bad. They decided to opt for a more electronic sound, which as previously stated, was not what I expected, I expected a more traditional Japanese sound to complement the setting. Everything else sounds good, and I don't have many gripes.
Character: 3/10
My main issue with the characters, aside from the previously mentioned issue that it tries to introduce too many characters for 6 episodes, is Saki. She suffers from a lot of the same issues as Rey in Star Wars, an issue I don't feel I need to elaborate on. The worldbuilding just warps around her, she's always in the right, she's able to control her magic powers right off the bat without any prior training to the point of *actual resurrection when we didn't even know this was a thing that was possible prior to." As previously stated, it also suffers from a lot of the characters being very forgettable, a problem that gets worse especially towards the end. I couldn't tell you a single thing about the character of the Daimyo, the magic teacher we meet at the end of episode 4, or the majority of the previously mentioned minor antagonists, aside from what I just mentioned.
Enjoyment: 6/10
I tried liking it, and it certainly can be enjoyed, but there's a lot of issues that become more and more apparent the further you get in.
Overall: 5/10
As stated in my opening, Yasuke is a resounding "Meh." Speaking solely on the visual and auditory elements, it's great as you would expect from MAPPA, but the writing has several issues. Watch it if you want, it's not something I recommend, but not something I'd absolutely say "do not watch this, ever."
