Sam is hovering in the sky on his harbinger.
There are dozens of bird puppets flying around him. Even more of them have went past him as they flew into the territory of the Nalvahan city. They successfully breached the air space and triggered the alert mechanism.
The mechanism has detected all the bird puppets and their energy levels, assuming that the threat is high, it sent an alert that a large army is invading, sending out the signal to bring out all the forces.
Just like Sam wanted.
He observed the movements of the city. He could see it. The turrets that are installed on the walls. Each turret occupied by three people at the late stage of the Divine plane initiation. It needs that much energy to properly activate.
The people noticed the bird puppets and are surprised.
"These puppets triggered alert? More importantly, I thought these puppets were creation of our employers. Why did that guy have them? And he came alone?"