The demon lord that was once feared because of his abilities, turned out to be a little green frog. He's too small that Titania couldn't help but squint her eyes due to the unbelievable appearance of the said demon lord. "No wonder you like using other people's faces."
Asmodeus grunts with his small voice. "I don't! I'm not like Leviathan! And this is not---" Titania stabbed the little frog with the sword. Her uninterested eyes stared at the being as she continues stabbing him with the sword, making Asmodeus scream in pain.
He's trying to accumulate the mana that he used on the whole city. Since he's been wrapping the city with his mana for a long. That's the reason for the citizen's behaviour.
Although demon lords usually don't die, they still feel immense pain like how normal humans do. The only thing that could kill them is divine mana. And Asmodeus being not a normal demon lord makes it worse.