I guessed right, starlight started saying stupid things
Starlight AND Imaginary and the hilarious shit is that I didn't even highlight, this is literally them losing it because they can't explain why Iori would ever lose to Yoriichi or anyone else in Demon Slayer and is just grasping on any and every little thing they can:
It doesn't say that. Hitting things with the flat of your blade is swordsmanship too.
Yeah, not with Black Keys they aren't:
Fate/stay night - Weapon Menu: Black Key [T]Black Key
Kotomine Kirei
One of the charms to repel devils used by the Holy Church.
It is a symbolic tool for the Agents, but not many favor using it as it is difficult to handle and has weak physical attack power.
Its effectiveness as a sword is low, and due to its length, it is used exclusively as a throwing weapon.
Most of the things they classify as "evil" are phenomena and ghosts, so the Black Key used to fight them emphasizes the ability to intervene spiritually, rather than physical attack power. The blades of the Black Key used by experts or chosen Agents are made from magical energy, and only the hilt is actually carried around. There are Agents that hide hundreds of Black Keys under their robes.
It was scattered through the whole lobby. This is also apparently omniscient narration here that indicates that it was smashed. And, as you said, the chief specifically was able to track the movements, barely.
This is also anime physics, and the rubble did have momentum as it was moving toward Hansa, and Hansa also leapt at it.
Bruh, you are fucking blind! There is no visible debris left over as he literally sliced them to dust as the narration states. You are going with people who can't see what he did over the narration itself!
Medieval german swordsmen writing books on how to sword disagree with you.
Mordhau, as Starsight brought up earlier, is literally using the sword not as a cutter but as a smasher. (Now they flip the sword around instead of using the flat side of a blade. IIRC that's more a defensive thing samurai did and i don't know of it being used offensively in any manner historically.)
Using swords for blunt force trauma is an unorthodox and inefficient use of them, but much like using a pistol as a club is unorthodox and inefficient. You absolutely can. (Hell if anything swords are relatively better than pistol whipping.)
I like how they bring up Mordhau when it's using a normal sized sword in an unorthodox fashion when Black Keys are explicitly not built for close ranged fights and aren't effective as swords...

Remember that this is a FICTIONAL SERIES they are trying to compare to Real Life but ONLY for this feat and not for, I don't know, DEMON SLAYER as well?
So with the context that Date Masamune from Sengoku Basara is one of my favorite gaming characters- holding six swords in two hands is also ridiculous. It hurts like hell and provides no benefit whatsoever in terms of physics or biology.
Still happens- and works- because fiction is ridiculous.
That said- there is a third option:
He did indeed 'cut' the concrete using the edges of the swords- BUT- he equally broke the slab into pieces beyond what cutting alone offered.
This enables both arguments to be correct. He cut using swords but the terms shatter and smash still hold merit as only part of the result was by cutting.
"Fiction is Fiction but these people who didn't see what Hansa did says he smashed it so we should ignore it over the actual narrator stating he used swordsmanship to cut them to dust and the movements Hansa does show no debris anywhere but dust"
Like come the fuck on people!
