I've got some questions to a sergal!
-Is there a war between northern and southern sergals???
-where can I find the history of sergals... I only find what they are but not what happened in their history
-are you friendly?
Yes, there was a war started by the Northern race, under General Rain Silves. They mostly eradicated the Western races, and marched towards Gold Ring in search of resources. There are also several other races on Tal, the name of that world.
Heres a general timeline:
Vilous Chronology - Vilous
That is the main Wiki for Vilous, so you can find out just about anything you need there. Other races, links to both the manga and novella, and the lore.
By canon, Sergal are generally more civilized if they interact with the other races closer to the city of "Gold Ring".