The suit of armor known as —The Unbreakable Cage—was designed to trap a magic user for eternity. Its interior was a labyrinth of silent gears and pressure plates. Every time Annerose moved, the armor moved with her, crushing her a fraction tighter. Every time she tried to cast a spell, the cold iron lining devoured the mana before it could form.
"Where is the Grand Mechanist? I need his heart to restart my own." koutetsu no majo annerose
He didn't say "executed." That was the cruelest irony. They couldn't kill her. Her bloodline was too valuable. The suit of armor known as —The Unbreakable