These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
In the first book, Damien spends more time thinking about Tarrant then he does even thinking about Ciani during their journey. Sure, it's nothing positive at first, but by the third book, him and Tarrant are nearly on First Name Basis and Snark-to-Snark Combat terms.
Magnificent Bastard: Gerald Tarrant. He's lived a thousand years and committed more than enough atrocities in that span of time, but he's so brilliant, charismatic, and determined it's hard not to at least root for him.
Moral Event Horizon: Essentially, Tarrant had to cross this to gain his immortality—he did it by killing his family. Damien spends most of the series trying to drag him back.
True Neutral: Loremasters like Ciani, who are more interested in knowledge for knowledge's sake rather than the morality in using that knowledge.