[It's a bit endearing to see how talkative Zagreus is, at least for the short amount of time Alucard has interacted with him so far. If he is being as honest as he speaks, anyway.]

Let me understand. You're escaping to the surface, you've seen the surface, but you're down here trying to escape again anyway. Is there a reason you return to the Underworld just to do it all again?

[As far as Achilles goes... that's an interesting matter on its own.]

I would say that perhaps he was too restless? But I can't imagine being your father's guard is anymore thrilling than warrior paradise. I suppose there would be a deeper reason.