Revelations from SHADOWBRINGERS

[Eloah]

Varis was fighting with his Uncle after Solas died remember as a war of succession. It's why after Varis won he quickly named Zenos as his Heir.

As to why Solas is so special is because he is Emet-selch. He was the one who stared the Garlean Empire. Per the Encyclopedia Eorzea he was a military genius and a pegasus and the Empire was raised after he hit 25.

I'm sorry he joined the military at 16 was a genius and made Legatus by 24 and became the first Emperor of Garlemald

That doesn't really answer anything though. Not that I was expecting one honestly. Besides, Solus was Solus until he became Emet-Selch. That doesn't mean much honestly. But maybe it's because after all that time he started growing attached to that version of himself. I mean the Tales indicates it somewhat.

It's been a while but did they indicate that the uncle was killed? If not he night resurfaced now, with Varis gone. Also the title of firstborn son alludes to there being a daughter in the mix, either between the two boys or before them, most likely. I wonder what will happen when we explore the empire more.