Images featuring at least three of Touhou's oni (or oni-like) characters.
Ibuki Suika, Hoshiguma Yuugi, and Ibaraki Kasen including her arm and original form are based on the Big Four Oni of the Mountain. Nippaku Zanmu is a regular oni, while Ushizaki Urumi is an ushi-oni.
Konngara is also often assumed to be an oni and is commonly treated as a fourth member of the Big Four, especially in works predating the later debut of Zanmu and Urumi. Remilia and Flandre Scarlet are sometimes given oni-like traits (as Remilia's title of The Scarlet Devil is sometimes treated as being comparable) but are vampires, so usually don't count when grouping. Kijin Seija is also sometimes associated with them, though amanojaku being significantly weaker means she's usually treated as a junior member at best.