Is New Testament 9 the most popular volume outside the fandom?

It might just be me but over the years (at least before Genesis Testament) I feel like I occasionally see more discussions about this volume compared to the rest. Even back when I first became a fan of Toaru after watching the anime in 2014-2015, I somehow knew about Othinus and the general story of 9 (For some reason i pronounced her name as “Or-thigh-Nass”). I feel like it’s a mix of the shock value of the volume and the incredible emotional storytelling. I find myself thinking about this story every now and then. Something about it has just stuck with me.

My favourite illustration in the entire series btw