Realization: Is the WoL a primal?!

[Berethos]

Its just when you manifest something, it can't be 'cloned'. Like say the beastmen summon ifrit. Another tribe can't summon their copy of them.

That's sort of how it works, and was explained in an interview in the last year or so.

Basically the summoning of a specific primal based on a specific belief set uses a specific essence/aether to create that primal (though how the initial essence is chosen is, afaik, still a matter of theory). Once it has manifested as a primal, future summonings based on that belief will use that same essence (which is why Ramuh has memory of older days, for example), and thus a second identical version can't be summoned while the first remains.