Can you therefore empathise with Kael'thas having been told by Vashj that his kin, his people were addicted to magic, just like the naga, and how they would need something to sustain them? Imagine his frustration as he tried to plan for their survival now that their primary source, the Sunwell, had been ruined by that bastard Arthas? The desperation that the Prince of Quel'Thalas must have felt - the last of the Sunstrider dynasty, the uncrowned King, unable to provide magical sustenance for his rac and in failing to do this, dooming his people? Shafted by the Alliance, mistrusted and barely tolerated by the Horde he enthrones himself in Tempest Keep where he waits for his kin to join him. He resides in The Eye, with the skull of his father, a Vial of Eternity and other artifacts he thinks will be needed to restore the Sunwell. Initially, his loyalty lies with Illidan but Illidan's insanity drives him to an about-face - he pledges loyalty instead to the Burning Legion which confirms his final betrayal of Illidan and, more importantly, his total betrayal of the his kin. His alliance with the Burning Legion leads him to summon Kil'jaeden from the Sunwell
So why is he my favourite NPC? He's not a particularly honourable character is he? Well I think that he is, but in a complex way. All his madness, his many changes of loyalties, stem from a desire to see his kin regain their rightful position once more. This will never be within the Alliance, certainly, but he had has to watch his once proud race reduced so severely in numbers, watch them be tolerated, rather than accepted by the other Horde races, watch then battle their addiction and watch the Wretched rise where once proud Sin'Dorei stood - could there be anything worse for a leader? If the world is bisected neatly into 'good' and 'evil' then Kael would probably sit on the 'evil' side. Once you accept that this is rarely the case, that shades of grey are more likely, and that good people do evil things and vice versa, then Kael becomes a good man who has done evil - for the sake of the greater good of his people: "Energy. Power. My people are addicted to it. Their dependence made manifest after the Sunwell was destroyed. Welcome to the future...a pity you're too late to stop it."