I think that the Luffy vs Katakuri fight just set the bar too high. For what its worth, King was a pretty cool opponent for Zoro, but at the same time I definitely felt like King could have shown more.
From King's first introduction, with his epithet being the 'Wildfire' and him covering head to toe in leather, i thought that as a Lunarian his whole body would be on fire the whole time, which is why he needs to wear the suit in the first place- to not be a fire hazard when around others. That was a cool idea that i thought would have been a bit more interesting than simply revealing King to be dark skinned.
The story of the Lunarians could have been that their entire bodies can be releasing flames the whole time and is used as a defense mechanism against wild animals just like Pearl, but in a cruel twist of fate, that special ability that protects them is the reason why they are instead hunted down by the W.G and Celestial Dragons because of how special they are and their special fire abilities. Maybe they were used as fire performers, considering Queen at one point called King a 'show off'. Or maybe King was endlessly tortured by the Celestial Dragons for entertainment, knowing King's flames would always protect him, but would also leave permanent burning scars, so King wears the mask and suit to hide them.
Now knowing that King was a lab rat experimented on by the WG, when Zoro initially broke King's mask (his upper half), i thought that it would reveal a Celestial Dragon slave mark or something, instead it just ended up being a pretty tattoo that didn't mean anything.
The jacket that King wears is similar to Shiryu's uniform when he was still a warden of impel Down, so i thought that King was also a former warden of Impel down, forced by the WG to commit torture and executions on his own people of the Lunarian Race, to test the toughness of their fire defenses- it could help explain why Queen calls King a 'torture loving freak' and add more depth and nuance to King's character. Queen as a former government scientist like Vegapunk also experimented on King, just like how Vegapunk experimented on Kaido to create a copy of his dragon devil fruit, and that is where the animosity between King and Queen comes from, that King was a former lab rat experimented on by Queen to gain access to King's lineage factor of the special fire abilities of the Lunarian Race. King being the Angel of Death by killing/torturing his own people, to free/protect them from the enslavement and torture of the Celestial Dragons. It could have easily made King a more deeper and more complex character. Yet Oda doesn't bother to expand nor explain this in King's flashback and will most likely reveal it in a SBS or Vivre Card like he always does.
Also in my head canon, i thought that King and Kaido's relationship started by King as a warden of Impel Down, came across a torture resistant Kaido when Kaido was sent there after he was captured, who after was impressed by Kaido's physical strength and durability and toughness after personally tortured him, King freed Kaido and they escaped Impel Down together to form the Beast Pirates.
Knowing that he is the last of his race, i expected him to be a lot more older, can you believe that King is 47 years old?? He looks like he's still in his 20's.
With King's katana being specially designed to grab and dismantle swords, i thought that it meant that King has fought many swordsman in the past, and would be particularly well versed in Armament Haki, and would also have Advanced Armament Haki- making King a complementary to Katakuri who specialized in Advanced Observation Haki. It would have been a good difficulty for Zoro to overcome since the hardest things that Zoro has cut still remain to be Mr 1's steel and a Pacifista. Zoro cut Pica's stone in Dressrosa, so i thought it would have been cool if Oda gave Advanced Armament Haki to King and having Zoro learning to cut through it.
King's fire could also have been hot enough to melt Zoro's sword, bypassing Zoro's armament Haki and adding more pressure to Zoro's fight with King.
I still don't understand why King's toughness weakens when the fire is gone, but he somehow becomes faster without the fire? There was a theory going around before the chapter released that King was indeed taking damage, but he used his flames to cauterize the wound, so after using the fire his speed slows because of the burning pain. Basically it would go something like this:
King with fire: invulnerable to damage but slower due to burning pain from flames constantly cauterizing and healing his wounds, as well as expanding the energy needed to keep the flames burning
King without fire: able to move faster and more agile due to less pain, but also more vulnerable due to fire no longer available to cauterize his wounds and resisting from taking damage
So many great ideas on King's powers and his origins, but alas all we got was a native guy in a gimp suit.
Love King's design. The dragon stuff was cool.
