Zyzz was a pretty huge deal back in the day. He was kind of the OG fitness 'influencer', years before there was the kind of established online fitness industry / social media culture we know today. His backstory was essentially developing from a skinny, introverted, WoW-playing nerd to an outgoing, energetic gym / party addict. He was very charismatic, and established much of the lingo and mannerisms still relevant to this day. It also helped that he had pretty great genetics in terms of his physique.
He produced/inspired lots of cult legacy content / memes, with the overarching message of 'We're all gonna make it'. Zyzz also inspired the trend towards the more 'aesthetic' / fitness model kind of look instead of hulking roided out BBers, which was a breath of fresh air back in the day and brought lots of new people to the gym, especially ones that could see themselves in his gamer background. His huge following certainly had part in the IFBB coming up with the more downsized/mainstream Men's Physique and Classic Physique divisions.
Honestly though, his early death did his legacy well, because it cemented his image in a positive light. Besides his charismatic, curated persona, he was pretty much also the blueprint of the vain, drugged-out, roided-out dunderheads discussed in this thread. He most likely would fit in quite well.
Chestbrah is his older brother and always tried to capitalize on Zyzz' popularity before and after his death. He's pretty much a lolcow in his own right, with legendary antics like f.e. the 'Jailbait Warrior vs Chestbrah and half of Sydney' episode.