User blog comment:AnonymousAK/Demon's Royale/@comment-7418318-20140715142255/@comment-7418318-20140715155808

There's also the possibility that if used against something other than Human or Celestial Spirit it would just do nothing. They did say that Zoldeo committed a taboo and was punished for it.

Human Subordination certainly seems to be the better defensive magic, since you can keep multiple Humans from being able to hit you, but offensively I'd say Macro is better. Since Caprico didn't fully control any of the Fairy Tail Mages, I assume fully making someone your servant like the ones he summoned takes time and/or some kind of ritual. There is of course the chance that he just didn't want them as servants, but it would be foolish to waste valuable battlefield ressources. They were after all stronger than his current subordinates.

It'd be interesting to see the two fighting over the possession of one of Caprico's subordinates. ^^

With Keith I wouldn't want to judge yet. We only know the basic outlines of his curse but that's it. We don't know if he can just snip his finger or needs a long ritual to revive a corpse. We don't know if that corpse would just be a flesh-doll or if it could use it's magic. We don't know if he can still fight when controlling a corpse or if it requires all his attention. We don't know if he can control only one, a few or many corpses at a time. We don't know if there's still something of the corpses personality left intact and able to fight against his control, requiring him to put more effort into controlling strong-willed victims.

Too many unknown for my liking, but maybe the upcoming chapters will answer some of the questions.