"I don't know what undead are so cannot really comment on the comparison. My intent was to prevent suffering."
And maybe SLIGHTLY to murder someone she found personally repellent, but not to cause him pain and the murder part is practically routine among powerful Dwellin, since you're reading her thoughts have all these anecdotal examples- The annual scheduled war which sees twenty percent casualties and everyone involved going home happy, death-matches for leadership changes in the more dangerous regions, pirates and warbands changing leadership practically daily in jolly good fun until someone who can keep it for a while ends up on top, casual murder attempts turning into negotiated trade deals after the fact-
Anyway, Allikreav was awful and had to be stopped. At least for a while. She ended up going after him a couple more times in future lives, not breaking any deals this time, until he cut it out with the torture enough that she hasn't heard of it happening in the last few hundred years.