As established, the Dragons were assholes who bullied everyone, The Gods came to the Humans defense, got their asses handed to them, and fled with the Humans. Dragons gloated till they had that same moment Mose's adoptive brother the Pharoh had when he had to be reminded that Egypt relied HEAVILY on slave labor from the Jewish Slaves they just let free! Though unlike his "Kill them all" despite the fact that felt very short sighted (you know the whole "chasing after them and going back on the deal with the people's who's god showed yours are NOTHING and killed your son to make a point after multiple warnings") The Dragons realized the Humans and Gods were doing important shit that eventually left them homeless once everything broke down cause turns out "being only good at fighting abd bullying was prehaps NOT the brightest thing to make a main trait of your race!
So they basically followed the trail of the Humans and Gods till they found the world they settled on, of course their "Survival of the Fittest" bit them in the ass as their numbers became SUPER FEW because of their death march to catch up to the two races location. So instead of ACTUALLY learning from their mistakes, they doubled down and decided they'll just use humanity as hostages and slaves instead to assure not another repeat of what happened before (Hostages against what Gods remain to keep them from leaving)
If I missed something or made a mistake, Plz do correct me BEFORE Edit disappears from this comment and I'll be sure to correct as fast as humanily possible! But hope the Recap helped jog memories! I swear this arc was too fucking long!