Konril is the name of the ice crystal (a spirit). I would be thankfull if someone could turn it into a character tag.
There are a few methods, but the easiest way to change a tag type is to put the proper prefix (found in the Tagging section of the cheatsheet) on the tag in a post's Edit box. For instance, just edit the post and replace "clean_x" with "artist:clean_x". Any user can change the category of a tag with 50 or fewer posts; larger tags need the assistance of a Builder or above user.
Creating the artist entry so that the artist can be properly searched for and auto-detected is a bit more in-depth and covered in howto:artist.