I just caught up to OP's latest manga chapter and saw a clip of roger shooting a 'Divine Departure'? move at oden, then crossing sword with whitebeard. Rogers divine departure, roger crossing sword with wb, and luffy's foot battle against dofy at dresrosa protecting law has the same color. Dofy's underling called the battle at dresosa Supreme King Haki colliding, so was gold roger actually shooting hakis at his opponents? Was there some theory or discussion already about this? I wanna read some infos.
Every strong weapon wielder in New World has a projectile slash attack ( Brook and Sanji developed theirs in timeskip and Sanji is counted because the dude was made to be a humanoid weapon and kicked at really sturdy shit all the time). Adding Haki to it should be feasible. I mean, that's the only real reason Zoro's new equipment keeps magnifying his attacks ( cause Wano doesn't look like a land of super blacksmithing tech. At all.). So the "curse" swords are probably just remnants of Haki armament usage layering on with each capable user ( since lesser ones would not just fail this, but many would also die for this rep to be created and maintained). Theoretically, strong enough Haki of many wielders could empower any sword, but better made ones would just keep it faster and with more quality since we saw "lesser" swords get busted or destroyed ( Zoro's sword at Enies Lobby rusted to nothing under a Rust Rust fruit user since Zoro back then couldn't use Armament Haki).