The birds who carry on the war

The majority of Magissens live in the southern half of the Nool Chain since the end of the third war. Most of the few cities and villages there live completely cut off from the rest of the world, but one of them has not yet laid down the arms. After all these years, they still want to carry on the fights, and end up attacking merchants and travelers in the surrounding region. They have refined the old-fashioned guerilla tactics, harassing caravans and stealing food and valuables. They don't take prisoners, have never accepted negociations, and are very good at striking where they're not expected.
Although at first, these kasiik wanted to conquer their lands back and push humans out as it was their objective during the war, their goals have changed quite a bit, and now they conduct raids on merchants, while leaving the lands untouched. They take valuables for themselves, to trade it with other kasiik communities, burn caravans and often kill people. Their actions have made the route so dangerous for humans, that merchants from the Sea of Ivory have to take the long way around to reach the north.
The Service, under the investments of most regions, has sent a large contingent to try and protect the trading routes against the avian ennemy. This massive military occupying the region has taken its toll on the interactions with other Magissen communities in the region, who see this potential invasion force as a significant threat.