He didn't teach her anything. Instead, he stood behind her and wrapped his arms around her, placing his hands over hers, which were holding her sword tightly right in front of her. He adjusted her stance and tightened her grip before leading the motion.
He activated Sky Splitter with her body as a proxy.
Lily didn't feel anything at first, but as soon as the sword started to descend, a massive weight pushed down on her entire body. It felt like she was covered in thick lead.
Before she was a quarter through, she sank to her knees, unable to bear the weight. Her sword crashed into the ground, leaving a small crater like it weighed as much as a boulder.
Panting heavily, she struggled to turn around and look at Squawks in confusion. How was that even possible? How had the weight of her sword suddenly increased so much?
Squawks smiled. Lily's expression reminded him of the first time he tried to practice Sky Splitter.