- Final Mutation
Also Known As
"Ain't long now bro...You will change your mind."
Tetsuo Nikaido (二階堂 哲雄, Nikaidō Tetsuō) is one of the two main antagonists of Yakuza: Dead Souls. He was the 3rd Patriarch of the Omi Alliance's Go-Ryu Clan, who took revenge on Kazuma Kiryu for what he had done to Ryuji Goda, and attempted to destroy Kamurocho with DD's help, turning the city into zombies and creatures using DD's Thanatos.
After he himself is injected with the virus, he becomes a giant creature which towers even the Millennium Tower, named the Oikazuchi Omega (完全体 オオイカヅチ, Kanzen-tai Oikazuchi).
Yakuza: Dead Souls
Nikaido is the new head of the Go-Ryu clan that has idolized Ryuji Goda for years. He desperately wants Goda to return as the rest of the clan is "helpless".
He is known by people outside the Omi Alliance as the person who gets things done.
His relationship with Goda can be seen as an extreme parallel of Daigo Dojima and Kazuma Kiryu's relationship, where he respects Goda so much, he wants to reinstate him into the Omi Alliance instead of managing on without him.
To this end, he recruits a mysterious man called DD to help lure both Kiryu and Goda back to Kamurocho, as well as destroy the Tojo Clan by the use of a new substance called "Thanatos" that turns people into zombies. When Hiroshi Hayashi gets wind of the fact that they are planning something, he confronts DD in their office. While they are talking, Nikaido comes in and shoots Hayashi, saying how rude it is of him to ask about another man's business. This is when DD injects Hayashi with Thanatos, turning him into the first zombie.
Near the end of the game, Nikaido tells Kiryu that he is holding Haruka at the top of the Millennium Tower in order to lure him and Goda up there. When they get there, they find Nikaido, along with Haruka and DD. Nikaido tells Goda that having looked up to him for all these years, he had now surpassed him by doing what Goda had failed to do, destroying the Tojo Clan.
After Kiryu and Goda defeat the ultimate Akhibari creatures, Nikaido tells Goda that he does not care if he dies, and never has: after all he laid his life on the line for years serving under Goda in the Go-Ryu clan. Suddenly, DD tells Nikaido that he has an ace up his sleeve. Just as Nikaido says "you ain't got shit...", DD betrays and shoots him with the tranquillizer gun, saying that he has just received a new, enhanced batch of Thanatos. He then pulls out a revolver and shoots Nikaido in the head. This transforms him into a monster that Kiryu must defeat.
Once Kiryu has defeated this form of Nikaido, he grows into a gigantic monster who bursts out of the roof of the tower, called Oikazuchi Omega. Kiryu kills him using an anti-tank rocket launcher.
- The use of the name "Omega" comes from the fact that it is the last letter in the Greek alphabet, and thus correlates to the ultimate boss fight as well. Thus the term "Omega" is also used for the most powerful boss in other JRPG games, such as Final Fantasy.