Japanese mixed martial arts promotion RIZIN FF announced that it will host a 16-man open weight tournament starting in September. The tournament hearkens back to the days when the now defunct PRIDE organization would hold these tournament to see which fighter was truly the best in the world. This tournament resembles the style of PRIDE so much that RIZIN has booked two of the biggest stars PRIDE ever had to participate.

Mirko “Cro Cop” Filipovic and Wanderlei “The Axe Murderer” Silva will both fight in the tournament an official for the organization stated. The grand-prix tournament will begin on September 25th and end on December 31st.

Cro Cop is currently serving a suspension of two years for violating the USADA’s anti-doping policy. He admitted to taking human growth hormones and was suspended back in November of 2015. The USADA’s jurisdiction does not reach Japan thus Cro Cop is allowed to compete in the grand-prix.

Silva has also had his battles with the USADA in the past. He received a lifetime ban in 2014 for his refusal to submit to a drug test and orderd to pay a fine of $70,000. The lifetime ban was lifted in May of 2015 and following a war of words and lawsuit with the UFC, Silva was granted his release from the company in January of 2016.

Reports have surfaced that RIZIN is also interested in having former UFC light heavyweight champion Quinton “Rampage” Jackson participate in the tournament.

The rest of the 16 participants are expected to be announced in the upcoming weeks.