Across six months, heats were held at MCM Comic Con London, Manchester and Insomnia 65 before the £5000 winner was crowned at EGX 2019 in October.
More than 50 people took part in the competition, with judging duties handled by top UK cosplayers Hannah Lydia and Kelly Jean.
Second place received £1,000 and third place £500.
Borderlands 3 shipped more than five million copies within five days of its release, according to publisher 2K.
Becoming the fastest-selling title in 2K history, the loot shooter sold over twice as many copies as Borderlands 2 achieved in the five days following its launch in 2012.
Borderlands 3 released on September 13, 2019 for Xbox One, PS4 and PC. On PC, the game is available exclusively through the Epic Games store until April 2020.
2K said the game’s strong early performance helped the Borderlands franchise – which had sold 48 million units worldwide as of June 2019 – surpass $1 billion in net bookings.
Borderlands 3 broke several other records for the publishing label. It was the most pre-ordered game in 2K history, and more than 70 percent of consumers who bought the title during its first five days of availability did so digitally.
Borderlands 3 is also the highest-selling 2K title for a PC game in a five-day window, and “broke pre-order records with the Epic Games Store“.