The Onion Spirit's Secret Identity

Looks like it involves Detective Conan, Newton's Coffin Lid Won't Stay Shut series, Adorable Foodies, and A New World of Malice.

Science of Deduction and Science (Detective Conan)

Newton's Coffin Lid Won't Stay Shut series (Katekyo Hitman Reborn!, Bungo Stray Dogs)

Adorable Foodies (Food Wars!)

A New World of Malice (Jujutsu Kaisen)

Flames, special abilities, stone tablets, cursed techniques, demons, the power of food, and "the real China"

Theme: Onions need to be peeled