u/DM_Me_Cool_Books

I'm primarily referring to Lindon, but also Mercy to a lesser extent. They were younger than Sophara, and went from Underlord to Overlord(and Lindon to Archlord) in a much shorter timeframe than she did. Yet her spirit was collapsing from the quick advancement, while they suffered seemingly no consequences. Was there any explanation?

Eithan advanced from Overlord to Archlord rapidly too but there's any number of explanations for Eithan being able to get around it

Edit: Thank you everyone for the answers, they're all very good