Cruel Reality
Last time, things proceeded in a way that allowed humans to match demons.
The initial invasion was thousands of Expert rank demons coming out at once, and it happened while the Emperor was battling to stop the Kingdom of Ribera and Roosevelt from gaining independence.
The timing was jarring, and the new enemies forced the internal war to a stop.
The kingdoms raised their banners in alliance along with their spears to face the newest enemies.
It was the first of events that would set off amongst a chain of events and all those events were grouped as one, because they preceded one another with months and then dubbed the Great calamity.
The Great Calamity in other words was a bundle of disastrous chain events that dealt catastrophic damage to Orion.
But something had changed, something massive had shifted.
The grandmaster rank demon entered Orion five months after the invasion began.
Mythical ranks came through years later, after dungeons and otherworld monsters had settled.