Emerald Sparrow looked rather indifferently at the sparrow on the ground, and as she stepped forward, Favo Runes flew out from her sleeve cuff. Soon, the runes landed on the unconscious sparrow's neck, encircling the Heart's Gem and forming a blue pattern resembling a collar.
That wasn't all. She then conjured a small Magical Barrier that enveloped the sparrow as if it was a dome of containment.
This was one of the Spell Techniques that every Magical Girl under the investigative institutes had to master and that only they could master: Magic-Sealing Arts.
The conditions for its deployment were quite stringent; it could only be used after neutralizing the enemy's resistance. True to its name, this technique could completely seal the opponent's ability to use magic and transform, with its duration fluctuating according to the caster's Magic Power strength.