It's actually made pretty clear in-universe during 3.0 and 3.4.

A primal is just a physical manifestation of someone, or a group's, fervent belief and desires. Ifrit is as he is because the amalj'aa wanted a leader to help defend their territory and conquer new lands. Ravana is as he is because the Vath wanted a leader to lead them on conquests. Etc etc. There is a basic principle the individual or group wants, which the primal manifests as, which gives the foundation of their personality. The same could be said to be true of their appearance.

It's been said that, after a primal is first summoned, it will continue to exist in the aether due to its worshipers. (This is likely the practical application of tempering - ensuring the primal will always have followers and thus always exist.) Theoretically if all a primal's followers die, and it is forgotten, it will truly die as well. No other way can even theoretically kill a primal for good.

However no primal comes out the way the summoner wants. Bahamut was a twisted mockery of the original, Shiva isn't the real deal but just a manifestation of Ysayle's idea of Shiva, etc. This usually makes them malevolent. Ramuh is the only exception.

Well... Alexander is too, ironic given he was summoned for nefarious purposes in the first place. Or perhaps that's the twist?


As shown in 3.4, the emotions of the summoner or group that summons a primal will also influence a given summoning. It still maintains the core appearance due to that appearance being iconic, but the psyche is different - theoretically you could have a genuinely kind and benevolent Ramuh, for instance. Theoretically.