Lilith Sahl in the light novels may be even more sadistic than Dietrich. She gave Abel a chance to save himself because she believed in him blindly... at a time when he was a murderous sociopath who killed millions.
Abel, and certainly megalomaniac Seth may be interpreted as other than 100% benevolent, especially considering their bloody past.
Ho Yay - Tons of it. Abel seems to have a thing for Tres, especially in the manga. Also Radu and Ion. And Radu and Dietrich (Radu couldn't shut up about how beautiful Dietrich was while he was being tortured). And Esther Blanchett and Shahrazad al-Rahman's very special friendship in both the novels and the manga adaptation. And Jane and Mary in the novels. And Jane with Esther and Mary with Paula in the novels.