And that's the end of the Mercurius Arc. Auto-translate has the next time hint being "Old Man" and I have no idea where to go with that. Nanaka maybe?

I think it's a sound effect of some kind, actually. Gave it my best guess for now and I'll fix it when the new strip comes out if it's wrong. Seems more likely than "old man", since, like, the only character to come to mind is that guy from the New Year's event, who... I'm not sure if they referred to him that way or not.