This he will introduce us to whole new level to haki far superior than any character shanks included who many delude themselves to be poster boy for haki lol
Im not sure if it's Haki really,
We've seen People Enhance their Blade with Speed, Strength, Soul, CoA, CoC ... etc
We've also seen them Enhance it with Fire, Ice, Gravity, Lightning, Poison ... etc
Yet it didn't make them reach Greatest Level,
Darkness is Strongest Element and CoC is Strongest Manifestation of Personal Power,
For Mihawk's Blade to do its job better than even these Two Powers, it must be Coated in something that completely ignores Nature or Willpower
I think Mihawk can Coat his Blade in Death itself, it's the Greatest Honor a Blade can have.
It makes so much sense for countless reasons.