In order to combat the opening of the demon gate, the first king of Filti, like a tyrant, cut off the then-emerging research on a new energy source—electricity; he turned to channel all the economy and talent into the line of steam.
This move was tantamount to strangling a revolutionary research in its cradle, and even after several centuries, there were still plenty of scholars who vehemently criticized this insane act.
But those soldiers of the Holy Church Army stationed along the coast of Drake Passage knew very well that without this resolute determination, there would be no flourishing development of steam technology, no steam tanks, no high-powered combat armor, no subsequent war weapons.
The demons wouldn't give humans the chance to slowly develop new energy sources.
Therefore, 70% of the empire's historical books contain this sentence—without steam, there would be no humans.