Tenz - he played COD when he was a kid, his name was ZZZZZombieZZZZZ (with 10 zs), that was changed to ten z zombie and then to Tenz (ten Z).

Asuna - when playing CSGO with his friends he came up with the theory that an anime name and picture resulted in playing better. He picked Asuna which is a character from Sword Art Online... he ended up keeping the name.

Hiko - named after a character from an anime called Rurouni Kenshin. Interestingly, Hiko has never seen this anime and only started watching anime a year ago (despite going by this name for many years in CSGO). *edited for accuracy.

Shahzam - his real name is Shahzeb. When he was in elementary school his favourite teacher drew a picture of him as a superhero called Shahzam.

Stewie2k - when he played FPS games with his friends they all had names based on Family Guy characters. His was Stewie after the baby Stewie Griffin.

Wardell - named after his favorite basketball player Wardell Stephen Curry.