Pena, nicknamed Preguiça meaning "Lazy",[2] has won several medals at both the IBJJF and ADCC world championships throughout his career, competing dozens of times at the highest levels of the sport and defeating some of the biggest names.

Pena defeated Erberth Santos in the co-main event of BJJ Bet on September 6, 2020[3] but injured his ankle in the process and was out of competition for the rest of the year.

[9] He defeated Josh Saunders and Max Gimenis before losing to Nick Rodriguez, and chose not to compete in the bronze medal match in order to save his energy for the absolute division.

[12] Pena was scheduled to compete against Craig Jones in the main event of UFC Fight Pass Invitational 4 on June 29, 2023.

They met once again the following year in the final of the absolute division at ADCC 2017, where Pena defeated Ryan on points to claim the title.

[24] Shortly after, it emerged that Pena had actually attempted to withdraw from the match due to the fact that his close friend and fellow BJJ practitioner Leandro Lo was shot and killed the night before.

[25] The pair then agreed to the same monetary bet for a potential fourth match at the 2022 ADCC World Championship, where Ryan was scheduled to compete in the over 99 kg division.

[30] Ryan withdrew from the event on just a few day's notice as a result of stomach issues he suffered during the week leading up to it, and was replaced by Nick Rodriguez.

[43] Both cases involved Pena being tested after participating in, and winning at, the IBJJF world championships in the previous year and being stripped of these titles.