So, if memory serves, this is right after the big Demon King confrontation, but before the final arc really kicks into high gear. Chapter 294 focuses heavily on Zeldris and Estarossa, or I guess, 'Mael' at this point? The emotional core is Zeldris trying to reach his brother, who's utterly broken after remembering his true identity as the Archangel and the tragedy that came with it.
It's a dialogue-heavy chapter, not a lot of action, but the tension is brutal. Zeldris is pleading, trying to anchor Estarossa/Mael, reminding him of their bond. Meanwhile, Mael is just shattered, grappling with the guilt of having lived as a demon and the sins committed under that persona. The art does a lot of the heavy lifting, showing his anguish and Zeldris's desperation.
Honestly, it's one of the more heartbreaking moments in the series for me. You see all this love and history between them, but it's completely eclipsed by this cosmic-level identity crisis. The chapter ends on a pretty bleak note, with Mael not really accepting Zeldris's words, setting up his descent and the chaos that follows. It's a necessary character piece, but man, it hurts to read.