As he struggles to save the boy from the forces of darkness, he also uncovers a Vatican conspiracy with world-ending consequences.

Source: https://screenrant.com/popes-exorcist-father-amorth-true-story-biggest-changes/

Chasing her to London, he realizes she is a CIA operative, and their second encounter becomes an international adventure with potentially world-ending stakes.

Source: https://www.digitaltrends.com/movies/most-disappointing-movies-in-2023-so-far/

Father's intimate understanding of the universe itself makes him a threat beyond what other world-ending antagonists are capable of.

Source: https://www.cbr.com/most-evil-anime-villains-ever-ranked/

Neither of the existing shows featured adult Avatars trained and ready for world-ending threats - Aang and Korra were both young and still mastering the elements when their villains forced them into conflict.

Source: https://screenrant.com/avatar-last-airbender-new-show-aang-adult-story/