Hi there. Good news and bad news (although neither is completely set in stone). Claymore season 1 actually had a completely different ending to it than the manga chapters it covered. To continue on, it would have to be completely re-written from that point on, so most likely the series has ended. The Guyver, on the other hand, is a very slow-to-release manga. Only recently have enough issues been released to make up a season’s worth of anime. Also, it follows the manga VERY close, with some improvements by Yoshiki Takaya himself. Some small things towards the end of the season seemed to be kept secret, which would be revealed in season 2. Too much story is left to tell and Guyver did to well for them to just abandon it.