[hider=Caster's 2nd Noble Phantasm]
[b]Name:[/b] Skofnung
[b]Quote:[/b] "Cut endlessly, oh guardians of Hrólfr! Here is your killer, here is your murderer, and in front is where fresh blood collects, waiting to be freed by you once again!"
[b]Rank:[/b] C (If it were used by its original owner, it would certainly be an A rank sword.)
[b]Type:[/b] Anti-Unit
[b]Range:[/b] 1-11
[b]Description:[/b] An imperfect version of the legendary sword of Hrólfr Kraki, equally legendary king of the danes. A blade of unparalleled sharpness, and haunted by the protective spirits of Hrólfr's most fearsome berserkers, numbering twelve in total. It is a supremely powerful sword capable of eviscerating even the most durable of foes...or at least it would be for Caster, if not for her violating two of its stipulations of use.

The sword carries with it two rules: That it is never to be drawn in the presence of a woman, and that the sun is to never touch its hilt.

As a descendant of the Vanir, her half-elf nature is like that of the sun itself. Merely coming into contact with the sword causes its power to drop in rank, and her gender causes its power to drastically drop once more. In addition, due to Caster being the one to personally cause the deaths of eleven of the twelve berserkers decreases the blade's legendary status, as it is the version pulled before the final Berserker, Vöggr met his end at a much later date. Thus, only eleven have "died" as far as the blade is concerned. Ordinarily, the blade would cut with the force of twelve men behind it, but Caster's version carries only eleven...and eleven men that have been weakened beyond what they are capable of.

The only way for this Noble Phantasm to reach true power would be in the hands of a man of true Danish descent, as then the stipulations would be lifted so long as the user didn't fight in the sun, or against or in the presence of women. Were Caster to perish, this blade, even in possession of another, would fade with her. 

[/hider]

Draft for my idea of Caster's weapon. As for "why" she'd have it, I'm going to pre-emptively say that I kind of interpreted it as that it is because she caused it to be haunted, as well as killing its original master. In the original legends, it was also frequently snatched from his tomb, so it wouldn't be uncommon for someone other than him to have it.