Who should be feared more? Klaus or Elijah?

They both have similar, but yet different powers as an Original Vampire. Elijah seems like the good guy, but Damon always just doesn't trust him because, with his Vampire instincts, he knows Elijah's plan of protecting Elena & her loved ones isn't that simple, I agree with my readers about Elijah is a Noble man that keeps his words, but what is he kills Klaus? Does he also kill Elena to get her blood on the Moonstone? Then Exterminate all her loved ones? Elijah isn't that simple, and Klaus? What could he be up to? Who should be feared more? Klaus or Elijah?