Sounds like mc run on a terminal window.
I do not have that combination of programs to test this.
Programs like mc may be written for ASCII, but will also tolerate UTF-8. They will pass through the codes to the terminal display, but may not understand the strange characters themselves. I doubt that mc has a need to understand these character meanings.
It is generally the terminal that does the display of characters.
It requires that the fonts be installed. If you do not have fonts that cover that part of Unicode, then (on X) you will get little boxes with code numbers in them. The standard fonts barely cover Latin-1 uses. They do not cover Russian, Ukranian, Arabic, Japanese, etc..