You'd have to use feats and comparisons. Give examples and build a strong case.
you asking for the sword feats or other sword feats? i made
this blog with her weapons (and some power and abilities she could get from the CRT that i was saving for it but i decided to make it into a blog now) but it can be explained that the weapons are stronger than their original object or person all the time:
the Oregon Sword only appears in
Chapter 221, first Yoru efforlessly cuts pochita in half, but he just regenerates, then Pochita clash his chainsaw agains Yorus sword, where Yoru struggles because of not being physically stronger than Pochita (the clash is based on their arms strength, not their weapons strength) then because Yoru is struggling, she uses the people of oregon for her sword slash so she can deal damage on pochita and be freed of the clash of his chainsaws, because pochita regenerates again she just ditches the sword as an ineffective way of incapacitating pochita by bypassing his regeneration, so she makes her nuclear punch to make a nuclear explosion that doesnt lets Pochita regenerate
about other swords being stronger than their original objects:
Chapter 98, makes the hand of the class president into a grenade thats makes an explosion, turn Mr tanaka head (a normal human) into a sword that can harm the class pres who as a devil, scales to small building level,
Chapter 107 she can make pencils into spears to attack Yuko, this spears are big enough to stab through a whole human body (like yuko did with one of asas bullies)
Chapter 122, makes a small ruler into a sword longer than the original ruler
Chapter 162, she makes a sword made out of a small scalpel, making it bigger and trying to hit Quanxi
Chapter 175, tries to hit Pochita with a sword seemingly made out of Sushi
Chapter 204, makes a whole building that Falling Devil made float into a sword, with Yoru believing that now that shes stronger, she could beat hear, and brings that building sword to fight, the building sword likely being stronger than building level as Yoru brought it up to a Falling Devil who lifted a building, if it was building level then it would be useless sword
all these weapons are from objects (or people) that yoru nor asa doesnt even care a lot, not being stronger from loving them, just her own weaponization making them stronger than their own mass
theres also:
Chapter 207, Yoru throws dozens of Weapons to Falling Devil, all of which pierces her, they seemingly made out of even everyday objects like a wheel, ice cream, a fish gills, a mouthless and hairless human head, a 10 yens coin, ETC
Chapter 216, Yoru makes the Chainsaw Man Whip Weapon from the accident devil, a devil who clearly should be much weaker than Pochita, yet yoru with it could cut most of Pochitas torso