Theodorou, a former UFC fighter, tragically passed away at the age of 34 from cancer.
The Canadian was suffering from stage 4 liver cancer, and only a small number of people were aware of this.
He was an experienced MMA fighter who took part in 22 fights. He started out winning 11 straight fights before switching to the UFC, where he had an 8-3 record.
Theodorou made his professional debut in 2011, and in 2014 he won The Ultimate Fighter, earning a contract with the UFC.
He won numerous notable matches throughout his career after triumphing against opponents including Eryk Anders, Dan Kelly, Cezar Ferreira, and Sam Alvey.
He made history by becoming the first fighter to be granted a therapeutic use exemption for medical cannabis by the British Columbia Athletic Commission, and he became well known for being an advocate for the use of medical marijuana in combat sports.
He was dropped by the promotion after a defeat to Derek Brunson in 2019 and later competed in the Prospect Fighting Championships.
At Colorado Combat Club 10, in December of last year, he defeated Bryan Baker by unanimous decision.