In Hawk Moth's lair, the large circular window opens from a negative emotion being sensed nearby.
"What could be more emotionally powerful than a young girl crying out for her brother's love? I love it!"
Hawk Moth extends his hand, and a single butterfly lands on its palm. Then he covers it with his other hand, filling it with dark energy. Lastly, he uncovers it, revealing the change of a butterfly from its white color to its dark color.
This process transforms a butterfly into an akuma.
"Fly away, my little akuma, and heal this girl's broken heart," he ordered, and it followed as it flies away from his hand to outside the window of his lair, ready to be prey on its chosen victim.
It enters Silvia's wrist guard, causing a moth-shaped emblem to appear on her face.
"Heartbreaker, I am Hawk Moth," Hawk Moth started speaking through her. "Your big brother doesn't see your true feelings for him? Well, this is just shameful. I'm giving you the power to exact revenge on him for not noticing your love for him. In return, bring me the miraculous. Do we have a deal?"
"If I can't have Sirius, then no one will!" Silvia said with rage on her face.
This means she accepted the deal, and she stands up from the ground as black and purple smoke came out of her wrist guard, covering her entire body. Once the smoke clears, her appearance changed.
Her skin is now green and her hair is now red. Also, her pink and white colored outfit changed into a knight's armor. Lastly, she is seen carrying a sword.
With her akumatization complete, Heartbreaker is now ready to exact revenge on her brother for not noticing her feelings for him.