Can't delete folder (in Windows 10) that contains special character

I have run into something that looks like a bug in Windows.

I have extracted a RAR archive onto my PC and the extracted folders cannot be deleted by any means!

My OS's language is English with some culture aspects of it set to Greek.

The character that seems to create the problem seems to be 'å'.

Here is a screen-shot that displays the problem:

Using DEL from the cmd doesn't seem to help.

When I try to delete the folder from Explorer nothing happens.

When I try to rename the folder from Explorer I get these weird messages :

Seems like a part of Windows thinks it's a file, while another part of it thinks it's a folder.

So, the question is: does anyone know what goes on here and any way to delete this thing?

EDIT:

As you can see, I have found a solution.
But if someone could explain to me WHY Windows has problems with this character while it generally supports Unicode, let me know. I would like to understand the internals of it... (that's the only difference from the other question, I guess)

Does NTFS support both Unicode and ASCII files names and that file used ASCII (for some reason)? Then if it used ASSCII, how on earth was the character displayed correctly in Explorer?