Adrian sat in the courtyard garden, legs tucked under him, watching the little lion cub chew on a carved wooden knight. The cub's golden fur glistened in the sun, his paws batting clumsily as he wrestled with the toy. Adrian laughed softly, reaching out to pull the knight away.
"Rex, that's mine. You'll break it."
The cub growled—not in anger, but in stubbornness—his teeth clamped tight. Adrian tugged once more, but Rex yanked back, tail flicking. They struggled for a moment before Adrian finally let go with a sigh.
"Fine. You win," Adrian muttered, crossing his arms. "But you're going to have to protect me if you keep taking my stuff."
Rex dropped the toy suddenly and hopped into Adrian's lap, curling up against him. The cub's warmth spread through Adrian's chest, soft and steady.
"You're… really staying with me, huh?" Adrian whispered. He stroked Rex's ears, and the cub purred in response. "Then I'll make sure I don't let you down. I promise."
The sound of footsteps broke the moment. Adrian looked up to see his father, Leon Leonhart, walking toward him, his cloak brushing the ground. Beside him was Celestia, her silver hair shining under the light.
Leon stopped a few paces away, his red eyes sharp as they fell on the cub. "So this is the spirit beast you've bonded with."
Adrian straightened quickly, nervous. "Y-yes, Father. This is Rex."
Celestia's smile softened the tension. She crouched beside Adrian, brushing his hair from his face. "Don't be nervous. Your father only wants to see."
Leon crouched down as well, studying the cub. Rex's golden eyes met Leon's without hesitation. A low growl rumbled in his throat as he pressed closer to Adrian.
"Protective," Leon said calmly. "Good. But dangerous if his master is weak."
Adrian hugged Rex tighter, cheeks puffing slightly. "I'll get stronger. I won't let him protect me alone. We'll protect each other."
For a moment, Leon's expression was unreadable. Then the faintest smirk tugged at his lips. "Hmph. Bold words for a boy your age."
Celestia giggled softly. "He's serious, Leon. Look at them."
Rex purred louder, nuzzling into Adrian's chest. Adrian smiled, running his fingers through the cub's fur. "He's not just a spirit beast. He's… my friend."
Leon's eyes flickered, just slightly, with something softer. "Then treat him as such. Train with him. Grow with him. A lion cub without fangs is prey. And a prince without strength is the same."
Adrian nodded firmly. "I will."
Rex, almost as if he understood, let out a tiny roar—high-pitched but proud. Adrian giggled, hugging him tightly. "See? He agrees with me."
Celestia leaned in, kissing Adrian's forehead. "You already understand what matters, Adrian. Not power, not control… but trust."
Adrian's cheeks flushed pink. "M-mother…"
Leon stood, arms crossing over his chest. "Don't let it get to your head, boy. You've taken your first step, but only the first. What comes next will decide if you're worthy of standing beside that cub."
Adrian looked up at his father, determination flickering in his young eyes. "Then we'll prove it. Together."
Rex gave another roar, louder this time, echoing across the courtyard. Leon smirked faintly, Celestia's eyes glistened with warmth, and Adrian—still flustered but smiling—felt his bond with Rex grow stronger than ever.
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Later that afternoon, Adrian carried Rex into one of the training halls. The cub wriggled in his arms, trying to climb onto his shoulder.
"Hold still, you're heavier than you look," Adrian complained, though a smile tugged at his lips. He set Rex down on the polished floor, and the cub immediately bounded in circles, paws sliding clumsily.
Adrian laughed. "You're like me when I first tried running with armor on."
The doors creaked open, and Leon entered, his heavy boots echoing. Celestia followed, her steps lighter but her eyes observant.
"You said you'd grow stronger," Leon said, folding his arms. "Show me."
Adrian stiffened. "N-now?"
"Now."
Rex stopped circling and padded to Adrian's side, golden eyes fixed on Leon as though sensing the challenge. Adrian took a shaky breath and nodded. "Okay."
Leon gestured toward the far end of the hall, where training dummies stood in rows. "Spirit beasts are not pets. They are partners. They answer their master's call. Prove that yours will listen to you."
Adrian knelt beside Rex, scratching his chin softly. "You hear that? We have to show Father we can do this."
The cub tilted his head, then licked Adrian's hand.
Adrian stood and pointed toward a dummy. "Rex! Go!"
Rex blinked, then charged—except instead of going straight, he pounced at a fluttering moth that had entered through the window. The cub rolled on the ground, paws flailing, before swatting the insect flat.
Adrian's face burned. "R-Rex! That's not what I meant!"
Celestia pressed her hand to her lips, laughing quietly. Leon, however, raised an eyebrow. "Easily distracted. Just like his master."
Adrian clenched his fists. "We'll do it again."
This time, he steadied himself. He remembered what his mother said earlier—not power, but trust. He crouched to Rex's level, meeting his eyes.
"Rex," he whispered, voice steady, "it's not about chasing bugs. It's about protecting me, protecting us. Look over there." He pointed at the dummy again. "Imagine that thing is trying to hurt me. What would you do?"
Rex's ears perked. He turned, stared at the dummy, and then his tail flicked. With a sudden burst, he sprinted across the hall and leapt at the wooden figure, claws digging into its chest. The dummy toppled with a loud crash.
Adrian's eyes widened. "You… you did it!"
Rex bounded back to him, chest puffed out proudly, and let out another roar—this time deeper, carrying a surprising weight for such a small body.
Leon's expression shifted, subtle but approving. "Better. You're learning to speak his language."
Adrian hugged Rex, burying his face in the cub's fur. "We did it, Rex! You're amazing!"
Celestia stepped forward, kneeling to stroke the cub's head. "And so are you, Adrian. You didn't order him. You guided him. That's why he listened."
Adrian looked up, eyes shining. "So… we passed?"
Leon snorted. "You stumbled first. But yes—you passed. Barely."
Adrian pouted, though the corners of his mouth twitched into a grin. "Then we'll pass better next time. Right, Rex?"
Rex purred, licking Adrian's cheek.
Leon turned toward the doors. "Don't get too comfortable. A cub may roar, but the wild won't fear him until he grows his fangs. See to it he grows them sharp."
Celestia smiled softly as she rose. "He already has the sharpest weapon, Leon."
Leon paused, glancing back. "…And that is?"
Celestia looked at Adrian and Rex, who were tumbling together in laughter and play. "Trust."
Leon's gaze lingered for a moment before he walked out without another word.
Adrian lay on the floor, Rex pawing at his chest. He giggled, hugging the cub close. "Hear that, Rex? We're already strong. We just have to keep growing together."
The cub answered with a soft roar, as if sealing a promise.
And so, in that quiet training hall, the bond between boy and beast deepened—one roar, one laugh, one promise at a time.