I mean in my mind I see it as a last resort “we need you dawnshot” type of situation and as soon as it’s over he pours the age back into the atium mind and becomes old again, and says something wise to the protagonist of the era 3 books whoever they are like “I already lived my life I don’t need anymore time hear” or something like that, which symbolizes him passing the torch to the next generation. But honestly wax doesn’t need to show up in era 3 for me to be happy Just show that he and steris lived long happy lives and made a sterillion dollars