Merlin was already greatly experienced in signing contracts. Controlling Number Three was just the same. When his Mind Power extended into the part where the puppet's heart was, he perceived a crystal-like, transparent sphere.
"Hum."
After Merlin's Mind Power entered the crystal sphere, the dark red puppet lightly trembled. Merlin could also immediately feel a sense of connection to the puppet.
This was a mystical feeling. Merlin was able to discern a powerful wisp of consciousness occupying the crystal sphere. However, he could now completely control the puppet and was able to stifle that burst of consciousness in the crystal sphere.
If Merlin wanted to, he could even extinguish the consciousness of the dark red puppet. Still, this would be of no benefit to Merlin. The dark red puppet knew many secrets and could be a great help to Merlin. Now that he could control Number Three, naturally, it was not necessary to exterminate it.