Originally Posted by
Inuhanyou
SLH literally does not say bad end. And you have to be as much of an asshole as possible to Arturia to even get her to even consider the grail over Shirou in the first place in that ending you refer to.
In regards to Mind of Steel, what makes it so interesting to me is that it is simply a choice presented to Shirou, and the true fork point of the route for his ideals. Kill Sakura and double down on a extreme world view, or dont, and go forward to eventually double down on another extreme world view.
I'm going to contradict my previous post a bit and say, although i consider Mind of Steel a very interesting ending full of questions to Shirou's life after that, it does not fit with Shirou's character in a vacuum. He is a determinator. He has to have an extreme world view full of self destructive tendencies. If he makes a choice, he will see it through to the end regardless of what happens, no exceptions, that is how broken he is.
However, as Shirou says throughout the visual novel, and Nasu has said himself as much, Shirou cannot live in the path of light unless Arturia is there to guide him. That is why she had to be taken out as early as possible. So Mind of Steel cannot canonically work with Shirou's character, because at that point, there was no Arturia to keep him on the path of the righteous.
IE, Mind of steel, while a legitimate End, is just as canonically possible as Arturia cutting Shirou's head off to get the grail, which are just as likely as Shirou regretting his path taken in any of the 3 routes, the percentage is so low that its not worth mentioning