So this is just a Fusion Timeline of Ninja Gaiden and Taimanin with a few changes. And you may notice some references to other Koei Tecmo's Games such as Wo Long Fallen Dynasty and NIOH's series. To answer that is simply that each one is linked. With Wo Long Fallen Dynasty pretty much pointing the Origin of Amrita/Elixir and Nioh using the Ryu Hayabusa ancestors and Nyotengu making appearance.
AncientTime:
Taimanin Clans, humans with supernatural powers as a result of very thin demonic bloodlines fight demons.
A pact between the Human and Dark World is made, that prohibits the exploitative interaction of both sides. Clans hunt demon or humans that break the deal. Ancient gods are banished thanks to a powerful ancient witch and ancient Dragons. Demons are kept a secret in the human world from this point.
Among the Present were members of the Ryuu no Ninja or as later they would be known as Hayabusa Clan.
184: Wo Long Fallen Dynasty: First mention of Amrita/Elixir By Consuming this mystical drug brings about an exponential increase in the body's Qi, granting strength that exceeds normal human limits. The highly coveted recipe requires human Qi in order to refine, and is known to only a handful of warlocks of the eternal way. To the common people, elixir is the stuff of fairy tales; only a handful of elites have ever obtained it. Its effects are diverse and range from raising the morale of an army to healing wounds. However, misuse releases an overwhelming amount of Demonic Qi that transforms people into demons. Legends tell of several kings in ancient times—including the First Emperor of Qin—meeting tragic ends after being overcome by elixir's Demonic Qi.
A man by the name Wo Long(Crouching Dragon/Protagonist) whose Village is swept by the Yellow Turban Rebellion stumbles upon a Blindfolded Boy whose identity is Zhuge Liang who resurrect him with a medallion and who is deeply involved with the Elixir.
Vigoor Empire: An empire which expanded upon Southeast Asia on what would be known as Myanmar, Laos, Thailand, Cambodia and Vietnam. An empire which Worshipped Fiends with its Highest Figure both religion and of state being the Vigoor Emperor. However, centuries later it would be disbanded in mid 1800s due to an isolationist policy, stagnation in military hardware and constant invasion from western nations. However, only the Empire's government was dismantled, its religions were Not.
The Infernal Priest Dagra Dai goes into Hiding:
794-1185-Heian Period: Ren Hayabusa fights a half Yokai and spares her(Hide) and take her as his. She would bear His Children, and After's Ren's death due Natural causes she leaves the Hayabusa Village to not be seen or remembered in history.
1274: First Mongol Invasion to Japan: the Mongols with aid of their Vassals Goryeon of Korea, after years patiently trying to bring the submission of Japan through Diplomacy, they decided to invade Japan. Among them were Sorcerers who produced the Elixir.
1573- Mochizuki Chiyome dies. Chiyome, a descendant of the 15th-century ninja Mochizuki Izumo-no-Kami (望月出雲守) of the Kōga-ryū school, was the wife of Mochizuki Moritoki, a samurai lord of Shinano's Saku District and himself a distant relative of Izumo-no-Kami. After Moritoki was killed in the Fourth Battle of Kawanakajima, Chiyome was left in the care of the daimyō Takeda Shingen, the leader of the Takeda clan and an uncle of her late husband. Takeda approached her and tasked her with creating an underground network of kunoichi (female ninja) for use against rival warlords.
1580-Above the Earth Dragons' paths that flows through the lands of Fuji, there lies a mountain that erupts with spirit. In the night, a faint white crown of light rests upon its peak. Lord Oda Nobunaga(1534 –1582), who challenged the heavens for control of the land, ordered that a stronghold be constructed at the height of the hollowed mountain.
Lord Nobunaga, he who had decimated the Ninja province of Iga, now sought the support of a select group of Ninja. In these times of war, even the most powerful feared the creatures that dwelt within the deep forests of Fuji. Lord Nobunaga knew of a superior clan, a group of warriors who have fought back the demons for generations. Known as the Hayabusa Ninja Clan, these descendants of the Dragon Lineage had long lived in these woods slaying the evil spirits that dared to show themselves in the sacred lands of Fuji.
Thus, the Castle of the Dragon was conceived; an impenetrable fortress to quell the threatening evil. The leader of the Hayabusa Clan, Shunden, shook hands with Lord Nobunaga, and promised its construction. The Castle was built, a strong face stared down at the evil menace. Thus, history recorded this shortly before the incident at Honno-ji that cost Lord Nobunaga his life. His Body was Never Found.
1581- Misao Yukishiro promised to Hanzo Hattori disappeared. This leads to the downfall of her Clan and absorption by the Mugen Tenshi.
1600-William Adams shipwreck in Japan while pursuing Edward Kelley. And with his appearance a high rise of demons came.
1601-William Adams execute Edward Kelley and sets sails to Ingland.
1602- William Adams Execute Johny Dee and returns to Japan using the name of Miura Anjin and marries Okatsu. And Joseph Miura is born.
Jin Hayabusa becomes the New Head of the Hayabusa Clan. Challenges William Adams which results in a Draw.
1608- William and Okatsu Receive the birth of their second child Sussana.
1614- Iga and Koga Clan take major losses after their last feud with some of their Vassal Clan taking the leadership mantle. The Iga by the Igawa, a branch of the Hattori clan. And Koga being taken over by the Koukawa branch of the Kikawa clan.
1620- William Adams Dies. His Son Joshua succeeds him as advisor to the Shogun. Amassing fortune and influence building a mansion somewhere in the mountains.
1624- Sussana is married of to the Akiyama Samurai Clan.
1635- Japan Shutdown to the Outside. Joshua Goes into Hiding with his family.
1914-1918 WW1:
1939-1945 WW2:
2001- Iraq War:
2002- Rise of the Vigoorian Religion in SouthEast Asia
2021-Myanmar Coup'd état: Myanmar Military took power in a coup over electoral fraud. With many people deciding to bear arms against the Military.
2024- Myanmar become the Republic of Vigoor.
2030-DOATEC Is Founded by Fame Douglas and Victor Donovan: Fame Douglas an arms dealer and Victor Donovan a weapon engineer founded company who would capitalize on mayor conflicts and expand.
2040-
June 15th Ryu is Born
July 3rd Hayate is Born,
August 7th Kureha is Born.
2041-Igawa Asagi is born
2042-Helena Douglas is Born,
2046-2050 Taiwan Crisis: China Invades Taiwan. (RPGX 2046)
USA assists Taiwan but both USA and China tried to avoid a full-scale war, so they only fought in the vicinity of Taiwan.
Japan joined a USA-Japan security treaty, to fight the Chinese over the territory. War spreads from Taiwan to Southeast Asia. People's Liberation Army landed in Okinawa with ground troops. The U.S.-China War effectively begins. (RPGX 2047)
Operation "recapture the islands" takes place, large scale battles involving the GSDF take place, which gave Yamamoto Nobushige, Hans Eduard Victor and Mine Funako fame.
USA bombs Beijing by air. "True Republic Youth" group start a coup in China. Russia helps China to stop the take-over. Chaos in China stops active conflict with Japan and puts a stop to the war. (RGPX 2048)
The European Union is able to negotiate a ceasefire as a third party. Russia assists, situation slows down as more nations are worried with a war with Russia as well. Relations reached a new low point. (RPGX 2049)
China and America transform as they absorb other nations and become the Chinese Union and UFS. (RPGX 2050)
Cold War between Chinese Union and UFS since then.
Doatech Position itself at the top with Rising international conflicts.
The Gates Manifests to the Demon World Manifest:
2047-Lords of Alchemy(LOA) diversify their portfolio as Ashtear Higgins becomes its chairman: a massive, high-tech corporation with enormous global reach and assets, everything from dental hygiene (such as toothbrushes) to military technology (including tanks). However, since the economic crash, its stock value falling due to the Taiwan crisis which resulted industry shakedown, thus they took a new way to keep themselves afloat by diversifying their portfolio manufacturing "anything and everything."
Start Producing Amrita a highly addictive substance produced from Vampire Blood, Researching to Produce Elixir And other questionable practices. With their Mayor Competition being DOATECH.
2048- Momiji is born. Kasumi is Born. Kokoro is Born
2049-Shinganji Kaede, she is kidnapped by Edwin Black. Shinganji Kurenai is Born. . Raidou's Bretrayal.
2050-Ayane is born. Honoka is Born. Felicia is born, Igawa Sakura is born. Yatsu Murasaki is born
2051-Nomad is Founded by Edwin Black. Akiyama Rinko is born
2053-
The Crimson Incident/Vampire Wars: Where Jo Hayabusa hunts a high vampire by the name Crimson and is badly wounded.
Igawa Revolt: Where Igawa Asagi after the death of her father she becomes head. However internal conflict with the Clan Elders led them to a civil war.
The Hayabusa Massacre: 3 months after The Crimson Incident. And had 3-way invasion by chance from The Black Spider Clan sponsored by Nomad, The Vigoor Empire and The Vazdah Cult. Each with its own objective, The Black Spider Clan/Nomad wanting to destroy the Hayabusa with any and all relics, The Vigoor Empire seeking the Dark Dragon Blade to awaken the Emperor and The Vazdah cult seeking the Dragon Eye to Awaken the Archfiends. While both parties were powerful against the Hayabusa, they had mayor losses cause none of them were allies cause each objective were against the other's interest. None of the invaders manage to fulfill their main objective however, the Hayabusa Clan as whole was no more. For the Head of the Clan Jo Hayabusa was slain by the Ninja Genshin and its Heir Ryu slayed by the Fiend Doku. Leaving behind the Shrine Maiden's as the only survivors. Who would take refuge with their close allies the Mugen Tenshin.
Mizuki Yukikaze is Born. Akiyama Tatsuro is born.
Ryu after being left for dead, his guardian spirit Resurrects him and is taken in by his mother's Clan the Koukawa by Koukawa Murai.
2054:
2056-Tokyo Kingdom is Build and Abandoned: after a couple of years its abandoned as failure to attract more investors.
2057-Koukawa Asuka is Born.
2059-Koukawa Massacre:
2060-
Raidou's Returns: Hayate is put on a Coma. Kasumi becomes the New Head of the Family and is Trained.
Oboro Ninja Troop Incident:
2063- Chaos Arena: In which a retired Asagi is forced back to action to investigate the Missing retired taimanin.
2064-
Kasumi Leaves the Village:
Tokyo Kingdom Incident: