Board Thread:Questions and Answers/@comment-73.195.103.45-20161215035830/@comment-25942629-20161218204249

According to Shinoa, there are two things that influence a vampire's basic power level:

1)  Bloodline, which is determined by the strength of the sire

2)  Age

Therefore, a vampire should never be stronger than someone of higher rank and should be unable to defeat a higher-ranking vampire except under extraordinary circumstances. A vampire's sire will always be stronger than the vampire sired, no matter how much time passes. Although Ferid and Crowley both have the same sire, Ferid is older and will therefore always be stronger than Crowley. The vampire hierarchy is pretty stable.

The only ones capable of fighting Urd one-on-one are the First Progenitor or Saito, who used to be a second progenitor. Third progenitors won't stand a chance fighting normally.

That said, it would be possible to defeat Urd by using tactics, like when Crowley and Ferid defeated Krul Tepes. Using magic, demons, seraphs, or other things like the Japanese Army could also even the gap in power a little.