I think they both grow to like each other in season 5.Well Anya doesn't like Willow either, in Fear Itself she expected Xander to not be friends with the scoobies anymore. In Something Blue, she asked Xander if she "can not be nice with her anymore" about Willow.
But i dont think Anya directly killed anyone in her original demon years and Anya thought Willow was vampire.Anya did try to have Willow killed, in addition to using her. So I can understand why she dislikes Anya. (For similar reasons, I think Xander has just cause, from his perspective, to dislike Angel beyond jealousy.) And unlike Angel, Anya did not express remorse for her past, and in fact treated her demonic past as her glory days. I wouldn't have trusted her either. Though yeah, Willow does have a jealous streak, as shown when she finds out about Cordelia and Faith with Xander.
That reasoning is completely lost on me, especially as some of what she bragged of was worse than death, and lead to far more deaths than Angelus could ever dream.But i dont think Anya directly killed anyone in her original demon years and Anya thought Willow was vampire.
Agreed . Plus Like been said before Anya was never sorry for what she had done . That plus her selfness at wanting Xander all for her self was another reason.I would like to say that Willow was the only one who saw the true face of Anyanka in "Doppelgangland." Like, everyone else knows she is a monster on a intellectual level, but Willow has seen the monster. Also, Willow still loves Xander, he's still her first crush, and even though she's with Tara now, some primal part of her still understands Anya as someone who's trying to take something of hers.
Anya was willing to be burnt to death and spend forever in hell to make up for what she did and again what lot people dont realise is Anya never actually killed anyone directly in her original vengeance demon years and D'Hoffryn himself made clear it Anya cross line in her vengeance when she got those people killed but since Halfrek sir Anya up thats why D,Hoffryn killed Halfrek instead.Agreed . Plus Like been said before Anya was never sorry for what she had done . That plus her selfness at wanting Xander all for her self was another reason.