I'll post what I've said in a previous thread regarding this matter.
One of One Piece's MAJOR theme is "Inherited Will". So What is "Will" Its Haki and ones goals and wishes.
So When you mention haki doesn't Store itself into blades like a power battery storage I agree; It doesn't store CoA into the blade from its previous owners but it does carry his Haki "Will"(Desire and Wishes).
Like Oden's "Haki" (Will, Desire, Wishes) through Enma to Slay Kaido or Kuina's through Wado Ichimonji to become the Greatest Swordman. Just like how Luffy carries Roger's "Inherited Will" through the strawhat.
Most of the issues arise from Translations and Terminology issues. Haki in the Japanese Language is a word that describes Many Things. Probably over 10 or more Definitions for that 1 word. When translated it starts getting confusing and it also doesn't carry the same whole meaning that word is suppose to mean in the original language.
Haki can mean Will, Spirit, wishes, desires, and many other things but in the manga it is also applied as an attack with what we know as CoA, CoO, CoC etc... and it get more complicated when Wano and Skypiea and other lands start using different terminology for the similar if not the exact same thing but in different forms.
Oda makes it more confusing when it doesn't really need to be and translations and transliteration makes matters worse.
This is the major problem in my opinion when it comes to "haki" discussions.
Most people don't know what they are talking about when Haki is mentioned or what context or what type of "Haki" is being referred to by the characters in the manga when a characters or objects haki is mentioned in case of Enma.
There a reason why Big Mom and Kaido Lost their shit when Zoro was about to do the same Dragon Slaying Attack Ryuma did.
Enma or Oden's "Will"(not CoA or CoC) was out for Blood that moment.