The bronze coffin!
The bronze coffin housing the devil lord's heart had been binded exactly like Kieran was now.
Kieran was unsure how the Shepherds had learned about such spells and magic circles.
They might have been at Alcatraz Prison, or the spells might have been passed down to them by older generations.
There was one thing that Kieran knew and could see clearly though. [Devil Transformation] could not be activated for the time being.
Just like he had expected.
"You are more reckless and foolish than I imagined, Bird of Death! Did you really think we wouldn't have been prepared after finding out that you have devil lineage? This is the Devil Sealing Circle. Even the devil himself would not be able to escape it! Are you ready now?"
Rainer had misunderstood the reason behind the shock on Kieran's face. Unable to hold himself back, he let out a proud laugh.