That's impossible.
As long as you give credit to the original artist, you can cover ANY song you wish, and she has not made any money off it, and therefore doesn't have to pay any royalties. If any company tries to own her music she can take them to court, and she will win even with the worst lawyer in the world. She said that the song belongs to Jeremy Soule and Bethesda, so she's set. She would only be brought to court if she took the credit for writing the song and released it for profit, then she can be taken to court (think Led Zeppelin)
Plus...it's just youtube....think about that ugly deformed girl that only sings other people's songs and has celebrities come on. She monopolized that and made money off it, and yet nobody tried to own her videos. Maluka on the other hand just recorded a cover without any profit, just for the sake of fun and sharing it with others (I think).
In other words, quit exaggerating, she doesn't need any help.
First off... that is an ugly GUY... if you are talking about the curly hair one... who just lip-syc's...
His videos were a violation. The artists took advantage of his popularity, and LET HIM continue... some of them.
Even on "American Idle"... most of the contestants get rejected because they don't have the actual rights to use music that they are entering the contest with. Thus, many good acts never got seen. (That is also the reason that you hear many old-contestants songs in new-contestants acts... because they were free to use, since "American Idle" owns the rights to those published works... since they "won" on the show.)
Karoke, is not fair-use...
Singing another's words, to a tune you created yourself, or one that is similar to the original... but at your hand... and your voice... is "Fair use"...
I also doubt that Bethesda actually copyrighted that individual song. If not... and it is just copyrighted with the game... then it is less than 5% of the games content, and is also "fair use".