This is a list of events held and scheduled by the Professional Fighters League (formerly the World Series of Fighting, WSOF), a mixed martial arts organization based out of Washington, D.C..
Kazuo Takahashi, ring name Yoshiki Takahashi (born March 13, 1969 in Ichikawa, Chiba) is a Japanese retired mixed martial artist.
 He has competed in many large MMA promotions, including the UFC, World Victory Road, Pancrase, and Pride Fighting Championships.
 Takahashi is best known for his incredible toughness, heart, and will to win.
 He has fought many top fighters in mixed martial arts, including Masakatsu Funaki, Bas Rutten, Valentijn Overeem, Igor Vovchanchyn, Ken Shamrock, Vitor Belfort, Heath Herring, Semmy Schilt, and Josh Barnett.
 His nickname is "Cannibal Yoshiki".
Former Light Heavyweight Champion Vitor Belfort was scheduled to fight Yushin Okami at UFC 122.
 However, UFC President Dana White said that Belfort would instead challenge Middleweight Champion Anderson Silva for the belt.
 Belfort was originally scheduled to compete against Silva on January 2, 2010 at UFC 108, but due to an injury sustained by Silva, the fight had to be postponed until February 6, 2010 at UFC 109 and April 10, 2010 at UFC 112, respectively.
 However, both fights were cancelled.
Daniel Acácio (born December 7, 1977 in Botucatu) is a Brazilian professional mixed martial artist, also current Superior Challenge Welterweight Champion and 100% Fight Middleweight Champion.
 He is most notable for his fights in PRIDE Fighting Championships and has previously fought for M-1 Global, Shooto, Pancrase, Impact FC, Jungle Fight, Fight Festival and Konfrontacja Sztuk Walki.
The 2010 M-1 Challenge season was the third season of mixed martial arts (MMA) fighting presented by the M-1 Global promotion.
 The season started on February 5 and will conclude with the M-1 Challenge XXII event on December 10.
 Unlike in previous years where competition was arranged entirely around country-based teams, the 2010 competition had a greater focus on individual achievement.
 Rather than the sixteen "country" teams of the 2009 competition, the 2010 M-1 Challenge featured eight teams representing four "continents" – Europe, Russia, Americas and Asia – with each continent having two teams.
 Four of the teams are drawn from the M-1 Selection events whilst the other four are selected from, and featured, veteran MMA fighters.
 Events held near the end of the year featured bouts to crown inaugural M-1 Global Champions in each of the five weight divisions.
Rick "The Gladiator" Glenn (born April 12, 1989) is an American mixed martial artist.
 He was the Professional Fighters League (formerly known as World Series of Fighting (WSOF) ) featherweight champion and Midwest Cage Fight featherweight champion.
 Glenn currently fights in Featherweight division in the Ultimate Fighting Championship (UFC).
Yuji Shimada (島田 裕二 , Shimada Yūji , born November 24, 1966 in Fukuyama, Hiroshima) is a Japanese mixed martial arts and professional wrestling referee, as well as professional wrestling booker, authority figure and occasional wrestler.
 He has refereed more than 1,000 contests in major MMA promotions including Pride Fighting Championships, Strikeforce, One, Rizin, M-1 Global in Russia, Dream, Deep and Super Fight League in India.
 He was formerly the head referee for Icon Sport, where he was also the head of the rules committee for Icon.
Yushin Okami (岡見 勇信 , Okami Yūshin , born July 21, 1981) is a Japanese mixed martial artist currently competing in the Light Heavyweight division of the UFC.
 A professional competitor since 2002, Okami has also formerly competed for PRIDE, Pancrase, M-1 Global, World Series of Fighting, and Professional Fighters League.
 He holds notable wins over Mark Munoz, Hector Lombard, Alan Belcher (twice),Anderson Silva (Via DQ), Nate Marquardt, former MMA fighter Evan Tanner and Mike Swick.
Ricardo Arona (] ; born July 17, 1978) is a retired Brazilian mixed martial artist.
 He has competed in PRIDE Fighting Championships and RINGS in his mixed martial arts career, and was a member of Brazilian Top Team.
 He is the former RINGS Middleweight Champion, as well as the 2001 RINGS Middleweight Championship Tournament Winner, and 2005 PRIDE Middleweight Grand Prix Runner-Up.
 In submission wrestling, he holds an undefeated record of 13-0, never losing a single point in a match, and is a three-time ADCC Champion.
 He has notable wins in both MMA and submission grappling competition over Tito Ortiz, Jeff Monson, Renato Sobral, Vitor Belfort, Mark Kerr, Kazushi Sakuraba, Wanderlei Silva, Dan Henderson, Alistair Overeem, Murilo Rua, Jeremy Horn, Guy Mezger, and Dean Lister.
World Series of Fighting 35: Ivanov vs. Jordan was mixed martial arts event promoted by the World Series of Fighting that was held on March 18, 2017 at Turning Stone Casino in Verona, New York.
 It was the last for the WSOF before it was rebranded as the Professional Fighters League.

Question: Vitor Belfort was scheduled to fight which competitor for various groups including PRIDE, Pancrase, M-1 Global, World Series of Fighting, and Professional Fighters League?
Answer: Yushin Okami