One example is 'Tsukiuta. The Animation'. It has characters with various expressions including some smug faces. The visual novel aspect of it also adds depth to the characters' personalities.
Artists should also consider the context. If the character is a villain, the smug face might be more menacing with a darker shading around the eyes. But if it's a more comical character, the smug face can be more over - the - top with a big grin and rosy cheeks. They can use different line thicknesses to emphasize the expression. A thicker line for the mouth when it's a wide smirk can make it stand out more in the visual novel.
Sure is! Frieren has a dedicated fan base thanks to its engaging plot and well-developed characters. The manga has attracted a lot of attention in the comic world.