What's weird is that Tiamat says something about dooming Bahamut to a fate worse than death while Hreasvelgr says that primals doesn't call any soul but is just a construct of the mind.

Why would Tiamat care about a fake Bahamut.

There is also this weird explanation as I heard about not being able to summon Ramuh Levia and Shiva Egi for some reason, as for anything link to primals I think I'll just go to "A wizard did it logic" and don't try to understand.