Lol I don't care man, Enma/Wado, it doesn't matter.
But every context enma has been used in has been with cutting/harming Kaido, not actually killing him.
Of course, it matters.
Saying Wado kills Kaido is random; saying Enma kills Kaido fits Enma and Oden's goals and fits the fact that Oden's other sword is suggested to slay the other villain of the arc.
The attempt was made already and it didn't happen.
So what? Lol.
Luffy has attempted to defeat Kaido how many times by now?
Does it mean that he isn't going to defeat Kaido? No, of course not.
I'm just saying from a ideological standpoint, it's better if it's his primary blade which is related to Enma. Enma is not his primary blade.
It's better if the sword that is:
-currently at its peak narrative relevance
-was used by a legend for a long time and is waiting to fulfil his goal (of killing Kaido)
-and is suggested to turn black
turns black this arc, instead of randomly mentioning a sword that has only been brought up this arc to emphasise Enma...
Making Wado black instead of the sword that has been mentioned over and over this arc is stupid.