Twitch streamer BushyGames has released a YouTube video explaining his build and methodology - and, of course, including the boss battles themselves. For the challenge, he gave himself free reign on strategies, abilities, and weapons, but only one attack per enemy or per boss phase (for those with multiple phases) was allowed. The (arguably overpowered) sorcery Comet Azur was also not allowed.
Fittingly, he named his Tarnished One Punch Man, before proceeding to bash every boss with a hammer. So what was the build? The colossal strength-scaling Giant-Crusher hammer was his weapon of choice and he spent hours scouring the Lands Between for upgrade material to max its stats. The Determination and Royal Knights Resolve weapon buffs proved invaluable, as did the Golden Vow Ash of War and Golden Vow Incantation. The streamer told Kotaku: “It was a fun run with lots of problem-solving, and I’m very surprised it was even possible in the first place. “On top of that, after posting the video I received plenty of comments and messages that let me know of other items that could have helped or improved the build, those included Ancient Dragon’s Lightning Strike with a faith build, the Rusted Anchor greataxe and Zweihander colossal sword - both of these have thrusting attacks which enable another damage buff called ‘counter damage,’ which is inaccessible on any non-thrusting weapon - and the Marais Executioner’s Sword for its unique Ash of War that can output a ton of damage. I didn’t use any of these items in the run, but they are all options that can perform better in some circumstances compared to what I used.” It’s certainly an impressive run, for the strategy as much as the skill. You can check it out in full below.