If I remember correctly, rather than lose his edge, it's more like he will realise that, if he were to let innocent people die for his revenge, then he wouldn't be better than those he wants to kill.
@Dezaki
Do you want another reason to hate the princess?
By the way, this is a small spoiler. It's not really important to the story, but it will be revealed later (or at least, it's like that in the LN)
Well, if you don't want to read it, don't read it.
And if I incite you to read it by writing this, then sorry.
The summoning required something like 100 sacrifices in both worlds to open the gate to the other world.
This means that the 100 that were closest to him at the moment of his summoning were killed and sacrificed.
Also, in order to ensure the safe passage of his soul, 5-10 people of his familly were also sacrificed.
This means that, even if he found a way to return to Earth, he would have nothing to return to.
yyeessh, parasites are a special kind of scary to me and here they are casually talking about putting worms in people and letting them breed till they pop. I'll admit though, if you wanted my mind to break from suffering, that'll do it.
@Dezaki
It was actually told in the beginning. She considered the MC inferior because he's a human from another world, even if he was a useful, powerful hero.
Huh, so he does make sure to try and help those that didn't wrong him, like that blacksmith family. So I guess are his only real targets his false allies, who happen to be leaders of this world?