That Time I Got Reincarnated as a Slime: Tensei shitara Slime datta Ken

[KrayZ33]

If he didn't need their lives for the resurrection magic, I imagine he would have only annihilated the leadership of the Falmuth army, possibly the knights of the strike force that killed his people, but let the thousands of grunts walk away. But then again, I guess that would have required that only a few people, and no named ones, would have died in the city. It would have made the whole first strike of the war look quite pitiful. If there was no resurrection option but Shion and all the others had still died, I reckon Rimuru could have still brought the hammer down on the Falmuth army quite heavily, to quench his wrath. However, he was shown to suppress his feelings in an earlier scene, so it's impossible to know for sure. He might have settled for killing the king, the commanders, the wizards, and so forth, while leaving most of the ordinary troops alive.

I don't blame you for finding war scary. That's a whole lot better than so many keyboard warriors all over the net glorifying it and acting like they would be real world Rambos if shit ever hit the fan.

That's what I'm saying.
I can completely and 100% understand his reasoning and why he does it.
He needs the "sacrifices".
It's just that this action is not the "good" choice. It's not what we teach our kids, if you want to call it that.
And I sure as hell hope that he knows this and won't turn into a big-fat hypocrite - that is all, because it's unbearable to watch someone who thinks he's rightous all the time, condemns others that aren't, and then acts like that himself when the first inconvenience shows up that is problematic to solve.