TV-Series
Description
Jin Tae-Jin is the adoptive grandfather of Jin Mo-Ri and the creator of a powerful martial art known as Renewal Taekwondo. He has a muscular build despite his age and bears several X-shaped scars across his arms and chin. His typical attire consists of loose-fitting, casual martial arts clothes with the sleeves torn off.

He is known for being stubborn and hot-headed, traits that he passed on to his grandson. Despite his ferocious and intimidating presence as a fighter, he has a soft and caring attitude towards those he considers close to him or his comrades. He is fiercely protective of his loved ones, especially Mo-Ri.

His background is rooted in military service. He was the captain of an elite group of soldiers trained in Renewal Taekwondo, known as the RE Taekwondo Force, who were sent on a spy mission to North Korea. During this mission, his entire squad was killed in an ambush, leaving him as the sole survivor. It was also during this mission that he encountered a powerful, gorilla-like creature. After a brutal fight, he defeated it, and the creature presented him with an egg containing a baby, who would grow up to be Jin Mo-Ri. He took the child in and raised him as his own grandson, living in hiding for many years.

His primary motivation is the well-being and growth of his grandson. He sent Mo-Ri to Seoul to participate in the God of High School tournament so that he could make friends and grow stronger. He is also driven by the desire to protect Mo-Ri from threats, even as he faces his own dangers.

In the story, Jin Tae-Jin serves as a legendary benchmark for power and skill. He is so strong that he once single-handedly defeated The Six, a group of the most powerful martial artists in South Korea, a feat that led many to believe he must use borrowed power, even though he does not. His reputation is so immense that the mysterious organization Nox went to great lengths to capture him, succeeding only by forcing him to sacrifice one of his arms, which threw off his balance and made him vulnerable. Even then, he inflicted countless casualties on his captors. Later, The King expresses a desire to make him the next God of Combat, further highlighting his immense strength.

His key relationships include his deep bond with his grandson, Jin Mo-Ri, whom he trained in Renewal Taekwondo. He also had a connection with Park Il-Pyo's grandfather, Park Il-Tae, who served under him in the RE Taekwondo Force. Jin Tae-Jin passed on a martial arts manual to Park Il-Pyo, blending his style with Taekkyeon.

Throughout his development, Jin Tae-Jin adapts to his circumstances. Imprisoned by Nox after losing his arm, he uses his time to mentally reanalyze his fighting style to compensate for his missing limb. He is highly observant and analytical, able to see the weaknesses in other martial arts styles, such as Northern ITF Taekwondo, and improve upon them. His most significant development is reaching a state called "no recoil" or "recoilless," a supreme realm of martial arts where a fighter wastes no strength. After losing his arm, he conceived of this idea to counter his inability to balance his body properly. In this state, every ounce of force is directed into the target with no wasted energy, allowing him to shatter the arm of the top god Odin from the inside with a single block.

His notable abilities are all centered on his mastery of Renewal Taekwondo. His physical capabilities are superhuman, as he has demonstrated the power to destroy mountains and entire landscapes with a single kick. His techniques include the Hwechook, a powerful spinning attack with variations like the 3rd Stance Hwechook, which targets an opponent's brain with three successive kicks. He also has original techniques like the Sonic Kick and Sonic Punch, which are delivered so fast they break the sound barrier. Other signature moves include the Dragon Seize, where he throws a pinned opponent headfirst into the ground, and the Ground Drawer, which rips up the earth to use as a shield. All of these abilities are performed without any form of borrowed power, making him one of the most formidable pure martial artists in the series.