
Unreal Engine (UE) is a 3D computer graphics game engine developed by Epic Games, first showcased in the 1998 first-person shooter video game Unreal. Initially developed for PC first-person shooters, it has since been used in a variety of genres of games and has been adopted by other industries, most notably the film and television industry. Unreal Engine is written in C++ and features a high degree of portability, supporting a wide range of desktop, mobile, console, and virtual reality platforms. The latest generation, Unreal Engine 5, was launched in April 2022. Its source code is available on GitHub, and commercial use is granted based on a royalty model, with Epic charging 5% of revenues over US $1 million, which is waived for games published on the Epic Games Store. Epic has incorporated features in the engine from acquired companies such as Quixel, which is seen as helped by Fortnite's revenue. In 2014, Unreal Engine was named the world's "most successful video game engine" by Guinness World Records.

Near the end of the fourth tournament, Nixon had defeated K2, officially becoming the winner of the fourth tournament. However, he did not care about this, as Nixon suddenly ran off to the Orion building shorly after the announcement. After taking down a handful of Orion’s guards with his bare hands, Nixon stormed into Ranzou Kihara’s office so he could spill out everything that he knows. Upon encountering Ranzou Kihara in his office, Nixon went face-to-face with the CEO. It was then that Ranzou told him the truth that he was looking for. Nixon was actually a failed experiment by Orion. A guinea pig for testing out the “perfect fighter” DNA on live subjects. He, alongside several other people, were stripped off their previous memories and then geneticaly reconstructed as “perfect fighters”. However, the experiment on him failed, as his body did not accept these changes, thus only giving him half of the effects of the experiment. Ranzou also told Nixon that his sister still works for Orion, now known as the psychotic assasin Mira, which explained her comparatively mellow behavior when fighting him. Nixon was shocked to know all of these revelations, that he did not notice the guards behind him. The guards then proceeded to escort Nixon out in the building, his mind still in disbelief. Nixon then spent a three-year interim under the custody of the Ikushimas after they offered themselves to take care of him. During this time, he also developed a romantic relationship with Kei, whom he had once met in the tournament. It all seemed like Nixon was now living the peaceful life that he had always wanted. Until one day, another series of attacks and kidnappings took place in several places around the world. All of them involving Orion. Rumors regarding these attacks trickled once again, but one thing was confirmed: Orion was definitely planning something. Realizing that it was the perfect time, Orion brings themselves back to the public consciousness once again by suddenly announcing the fifth Sentoki: Global Martial Arts tournament. With the promise of a much bigger prize pool than ever, the tournament attracted lots and lots of participants from all over the world, and interest in Orion skyrocketed once again. The announcement that Ranzou Kihara himself would be the last adversary that the participants would face in the final round of the tournament only added more fuel to the fire. To Nixon and the Ikushimas, it was like the golden opportunity that they have all been waiting for. The chance to finally crush Orion once and for all. Thus, the three of the decided decided to join the tournament. Each for their own reasons: Shin, to finally exact his long-awaited revenge for his deceased mother. Kei, to find out the whole truth about her relationship with Ranzou. And Nixon, to save his sister and regain their past memories.
