The First Spinjitzu Master

At the top of a high mountain, the Master built the Monastery of Spinjitzu—a sacred abode that became a center for martial arts training, meditation, and elemental philosophy. There, he taught Wu and Garmadon energy control and gathered the Elemental Masters to protect them from threats.
The monastery symbolizes harmony, home, and protection from all dark forces. After his death, the Master rested in the secret Tomb of the First Spinjitzu Master, located in the depths of the Infinite Sea. The tomb was protected by deadly trials, which only those who truly mastered the philosophy of Spinjitzu (saving an ally above one's own victory) could pass.
The Tomb contained the Realm Crystal and the body of the Master himself. Even after death, his spirit abides in a special dimension between life and death, from where he watched over Ninjago and once personally appeared to his grandson Lloyd to impart the remnants of his Golden Power to him to save the world.

The First Spinjitzu Master raised two sons, passing on his great powers to them:
Garmadon (Eldest Son): Inherited the predominant power of Destruction (the Oni line). His Master taught him self-control and respect for balance. However, as a child, while trying to retrieve his brother's lost sword, Garmadon was bitten by the Great Devourer. The Devourer's venom poisoned his blood for years, awakening the Oni darkness within him and turning him to evil. His father tried until the very end to heal his son and guide him onto the righteous path.
Wu (Youngest Son): Inherited the dominant power of Creation (Dragon lineage). He grew up more obedient, wiser, and devoted to his father's teachings of protecting the world and maintaining spiritual balance.
Their father loved both sons equally, taught them Spinjitzu, and tasked them with protecting the Four Golden Weapons after his death. The tragedy of his family's disintegration and the brothers' feud became his greatest internal pain, but he believed that their line would ultimately bring the Great Green Ninja to the world.

Creation of Ninjago and the Weapons of Creation: With the Golden Weapons, he forged the continent of Ninjago and founded the world's elemental system.
The War with the Overlord and the Splitting of the World: When goodness was born in Ninjago, darkness manifested into the essence of absolute evil—the Overlord. He created the Invincible Stone Army. Realizing that defeating the Overlord in direct combat was impossible, the Master used ultimate magic and split the single continent into two: Ninjago and the Island of Darkness. This trapped the Overlord's spirit on the Island and restored balance.
Invention of Spinjitzu: Created the martial art of Spinjitzu—a vortex of elemental energy capable of creation or defense.
Elemental Power Transfer: Empowered humanity's finest defenders with elemental powers (Fire, Ice, Earth, Lightning, Speed, Amber, etc.), forming the first Elemental Masters Alliance.
Creation of the Realm Crystal and Tea Seeds: Left behind rare artifacts for traveling between worlds and protecting Ninjago.

The First Spinjitzu Master was born in the First Realm—an ancient reality where two races eternally warred: the Dragons (representing Creation) and the Oni (representing Destruction). He became a unique being—half-dragon, half-Oni. Realizing that neither faction sought peace, but merely sought to use his hybrid power to achieve victory, he refused to take sides, removed the Dragon Armor, and departed his homeworld using the Realm Crystal he had created.
After wandering through 16 worlds, he found a world covered only by an endless ocean, where the serpent Wojira raged. Teaming up with the Merlopians and islanders, he helped stop the monster (thanks to the sacrifice of the first Water Warrior, Niad). The Firstbourne then created land and created the world of Ninjago itself.
In the Golden Peaks, he forged the Four Golden Weapons (the Sword of Fire, the Scythe of Earth, the Shurikens of Ice, and the Nunchaku of Lightning), which contained the primal forces of Creation. By nature, he is deeply wise, patient, and peace-loving. Within his soul, a constant struggle rages between the light of the Dragon and the dark of the Oni, yet he has chosen the path of Absolute Balance and service to goodness.