The Legion of Justice
Strangely, this spell resonates with this world, your own power, and the power in the immediate area. Unfortunately, it does cause a backlash.
As your now golden blade pierces the demon through, sending it back to wherever it came from, you get a vision of a terrible golden entity with multi-winged angels around it, and legions of people worshiping it because that is what they were told to do. You hear only one word, spoken clearly: "OBEY!"
When you vision returns, the demon is gone, and you feel a disconnect with your magic. It's not as strong as Chang's lock though, and you know it will fade much faster. Likely within the day.
The Legionnaire is soon joined by others, who see him walking up to Thirteen. "You belong to Citizen Anthony, correct?" The Legionnaire is speaking to Thirteen. "If you can hear me, good work, citizen. You have upheld the Law of Justice well. And if you can't hear me...machine, tell him he did well."
Thirteen did not respond, except to give a quick salute in the manner of the Legion.
A dark-skinned man wearing a white longcoat with a golden eye emblazed on it steps through the forming Legionnaires. "The demon was slain?"
You realize they cannot see you as they are speaking. The Legionnaire who was speaking to Thirteen replies. "Well, it is not here, is it?"
The man in the robe strikes the speaker in the head with a swift hook, knocking him down. "Find the others, get order back in this city. Brand the cowards involved according to the Law of Valor, and enforce the others as needed. We might not be finished yet."
He's looking down at a bit of blood that is pooling at your feet. He kneels down to it, studying it intently and sweeping his gaze to where a short trail has formed during your movements against the demon. He gives a command without looking to the other soldiers. "Dismissed! Get back to your posts!"
They leave, and it is just Thirteen, this man, and yourself.