I feel like what Frixio was talking about there had to do with the fact that Ramuh was summoned *to* temper the Sylphs; he just wouldn't be able to know that it was specific to this summoning, not in general.


I also feel like each Primal has their own rules on tempering. Ifrit tempers whoever he can, being insecure and believing the more followers he has, the more power he gains. Garuda probably believes her tempering to be a blessing only for her children, and a means to turn her greatest enemies to her side (an eternal punishment for their misdeeds). Leviathan only tempers landwalkers. Thordan will temper anyone he needs to.