Claymore was a popular anime series that ran from 2007 to 2008. It had twenty-six episodes, but only three of them were considered filler content by fans.
In this world, there exist demonic creatures called Yoma and half-human/half-yomas known as the claymores who protect humans against these evil beings; however, they also have to watch out for their savage impulses. Claymore was an exciting anime with incredible action scenes between demons and human hunters to stop other demons from getting into populated areas or doing harm.
The show is set up to enjoy without having seen anything else because each episode contains something new.