LordBucket, Eotyrannus, I find it very hard to argue with you two as the points you bring up are perfectly valid, but refusing to fight will not change anything. We need to fight.
But I do not say we need to murder our opposition. We must simply show them the truth. Run propaganda campaigns. "Corrupt" heroes. Do not let our minions hate their enemies.
The murders we have committed before were a result of our heroic thought processes, but now we can change. We can realise that even the life of our daughter isn't worth a thousand dead people. We can learn how to make difficult choices and accept the chains of commanding. We learn to follow our own goddamn standards!
Sailing off into the sunset is a very, very tempting choice, to simply not fight in such a violence-ridden world. But I say that we should kepp our overlord mask and become a better person.
EDIT:Yes, become a True Hero, but keep the position of the Overlord, because we will need it to at least survive. But change internally. Really do start fighting other criminals, and poverty, and famine, and whatnot.
You know, not that I look at the shitfest that is this world, I realise that what we have is the classic story about one group going against the other, and then the hurt group retaliating and then the revenge spiral giving birth to hatred and those who fight monsters becoming monsters themselves and so on. To stop the hatred, we need to be above it, not subjected to it.
In short, my position is that we should have a revelation and become a better person as an overlord. One that does not slaughter innocents to save one person no matter how dear that person is to him.
As LordBucket said, violence will not change anything, but apathy will not change anything either. We need to become the first person with considerable power in this world that does not hate his opposition.