One day the life of the warrior took an unexpected turn. He stumbled upon a mother dragon and her little dragonling. The warrior didn't like the way the mother treated her child and decided to go against his own nature and slew the mother dragon, thus saving the dragonling from her clutches. Buster Blader also took the dragonling with himself, fearing it might not survive in the wild all alone. Buster Blader started to form a powerful bond with the dragonling (the Buster Whelp) and they eventually became best friends.
The Buster Whelp became a trusted companion to the warrior in his countless battles. With time it became noticeable that Buster Whelp was changing, with every battle it became more vicious and ruthless, tainted by its increasing devotion to his friend. This eventually escalated to an obsession and Buster Whelp became Buster Dragon. Buster Blader was becoming very concerned with the changes Buster Whelp was facing and wanted to see his old friend come back again. After he failed to return his friend through words the warrior realised the only way to help him is through a battle. The two began their battle but at one point Buster Blader started to hesitate, realising that he was battling his devoted companion from the past. He started seeing the happy moments he had with his friend through the reflection of his sword.
After a prolonged fight Buster Blader had to admit that the only way to free the soul of his former friend from the corrupted dragon is by killing it. He reluctantly did so and slew the Buster Dragon once and for all. The body of the Dragon started to glow and Buster Blader fused himself with the soul of his former companion - Buster Whelp, thus becoming united with him once more and gaining new powers in the process. He became Buster Blader, the Dragon Destroyer Swordsman.
- This monster appears in the artworks of "Dragon Buster Destruction Sword", "Robot Buster Destruction Sword", "Wizard Buster Destruction Sword", "Destruction Sword Memories", and "Prologue of the Destruction Swordsman".
- Buster Whelp is the rival version of Dark Magician Girl.