Nothing indicates that he meant to use KA on more than Fugaku anyway. So, yes, it's very unlikely that he spams KA like nobody's business.I can agree with this. At the very least, the claim that Shisui intended to use KA on every Uchiha conspirator remains extremely unlikely/is contradicted by manga events.
Ocular genjutsu doesn't seem to be detectable, as Sharingan can easily see the flow and had Itachi not warned Kakashi what he was about to do, he would have had no clue what was going to happen.I'll let this one go, then. But I still feel like the claim that "Kotoamatsukami is undetectable," which the other posters were making, can't be taken at face value. I pretty much agree that Kotoamatsukami can't be sensed while it's in action, unless someone sees the chakra flow and puts two and two together. But as far as casting it goes: for them to act like it's so definite or ever even confirmed that Shisui's use of Kotoamatsukami doesn't have a casting time or that this casting time cannot be detected doesn't make sense to me. I was only ever arguing that the casting of Kotoamatsukami being undetectable isn't canon.
The second image makes it clear that Ao had seen Shisui cast KA, otherwise, it would make no sense. As he knew the complete workings of the Genjutsu. It seems to be less than a coincidence and more along the lines of an exposition used by the author to explain that "this is how KA works," as we were never going to see Shisui use it anyway.I don't understand how when Shisui hypothetically casted KA for Ao to witness it matters, since ten years definitely passed between the time Itachi received Shisui's eye and the time that the eye finally casted KA on Itachi (Sasuke was 7 or 8 at the time, right? By the time the KA is activated, Sasuke is 17).
Sasuke was 8 when it happened. The timeline, doesn't fit as we don't know "when" he used it and when Ao witnessed it. He could have been any time in the past. We also don't know "why" Danzo went for Hashirama cells, when Shisui never used the eye on him.
I am suggesting that if the eye was functioning, then why did he go to Orochaimaru to get around the cool down period, as he needed the eye himself? Which is what I am saying that the timeline doesn't fit at all. Which eye did he try using and which was under cooldown period? The eye he gave to Itachi was under cooldown, yet he claims that he only "tried" using it on Danzo, which means he never actually used it.As far as why Danzo would try to subvert the cooldown period, it's not like he immediately went to Orochimaru as soon as he got the eye, as far as I know. He could have experimented with KA and discovered the cooldown on his own. Alternatively, he already knew about the cooldown, just like he knew about Kotoamatsukami already, and simply decided that it was something he wanted to avert for his future use. But I feel like I don't perfectly understand the point you're making here.
^ It's a pointless debate. The manga is a mess in regards to the cool down period.