[@Holy Grail] [@ConstantlyComic] you guys should seriously check out the Badass of the Week website, its a great resource for Servant ideas. This website is basically nothing but a giant list of potential Servants. Most are from modern times, but about a third are either historical or mythical enough to fit the bill. 

I learned about the Necromancer Skuld from him, as well as Yuknoom Ch'een II and a looooong list of others that I hope to play someday but probably will never get to.