Mike I know you want to enslave and fuck Sakura and Rider in their bungholes all day long
No, I do not (the first part, certainly).
but at least apply your own sense of morality to them.
I am. My morality is not utilitarian.
Killing an entire city's worth of people to "protect" someone (who doesnt need it, wouldn't gain from the "protecting" and wouldn't approve of it either) is something that is beyond all sense of "moral". It's sick.
It is wrong, yes, I would absolutely agree with that. But, I don't think it as bad as killing people for fun or for your own selfish gain, and nor do I think that it is magically OK to kill millions of civilians because they are the "enemy", yet you guys seem to be arguing that it is.
If Rider attempted to kill the entire city to save Sakura, I would attempt to stop her doing so. But, I don't consider her evil or worthy of death just because she wants to protect Sakura (who, as you say, would prevent it anyway). Particularly given how long ago she lived, and how different morals were then.
Further, killing the entire city to protect Sakura is
not as bad as wiping out a large chunk of it because you're having a fun battle. At least Rider has an laudible intention, even if her means are extreme.