According to researchers from Wowhead, the best covenant for the majority of class specs is Kyrian. I hear it's mainly because of Pelagos giving players a 3% versatility buff that is easy to keep up at all times during combat. It used to be 5% but even after being nerfed to 3% it still remains a very solid option for most specs. Will you be picking it? Seems inevitable that it's going to get nerfed and make everyone move over to the next, best covenant, and so on. I wish choosing covenant was only for cosmetics, mounts, pets, and quality of life bonuses.