"It's not the only reason," he corrects, in the end, being petty enough to. Will he explain? No. "But I don't expect you to truly understand. I don't expect anyone to, really, and that's fine." How can they? No one survives with The Scourge long enough to be lucid about the experience. They don't understand what it means as a daemon to feel it coursing through their very veins, whispering the desire for darkness and ruination directly into their brain. His soul is tainted with it now and there is no hope for him anymore.

Gladio isn't wrong that some of his reasons are selfish. Personal. Yet, The Scourge also hurts him the more he doesn't hurt others. That pain needs some release now and again. The best way he's found is to just follow that compulsion. And the more people hate him? The easier all this will be, he thinks, to just be a monster to be eradicated. No one needs to feel sorry for him or worry if they're doing the right thing by ending his miserable existence- They are. Even Ardyn would say so.

"Good is something anyone can be, but unfortunately it doesn't mean the world will be kinder to them for it. I learned that lesson the hard way as you saw. So, why bother continuing to try and be good if we're to suffer anyway? Might as well do what I want and make it at least somewhat entertaining until the curtain falls. When it does, the world will remember you as the heroes and me as the villain- That's just how it's meant to be."