It was cool to see Marco actually holding his own against an Emperor.
His Phoenix flames seem to damage Prometheus, which was interesting. We already know that they have a restorative property for physical injuries. I wonder if the fact that he damages Prometheus in any way relates to the fact that Big Mom’s Devil Fruit derives its power through transferring souls or life force from one person to another.
Big Mom retreats from Marco, which was interesting. We saw that she was unable to use Prometheus, and says she’s out of souls to use. The fact that she doesn’t even try to use Napoleon suggests that it is indeed the soul aspect of her Devil Fruit countered by Marco’s flames rather than the fire element to Prometheus attack.
I’m still unsure what role Big Mom is going to play in the battle. Being infected with Queen’s Ice Demon plague would prevent her from reaching Luffy and Kaido and make the battle in the Performance Hall even more chaotic.
I’m guessing Marco’s phoenix flames will be in part the solution to curing the virus. We see that Brook was touched by one of the ice demons, but because he’s just a skeleton, he’s immune to the virus. Chopper seemingly has a revelation, but is infected before he can say more.
I was hoping Chopper’s skill as a doctor would shine here, but it seems Marco’s now more likely to save the day. Perhaps Chopper will communicate some critical detail to him before succumbing to the virus. So Marco will play a role in hindering the spread or healing the Ice Oni plague. It makes sense since:
1) He still doesn’t know what role he’ll play.
2) The fight against Prometheus mentions that he has a “special type of flame”.
3) Marco is placed in the position wherein he hears people screaming about the Ice Oni.
4) Chopper caught the plague. Might not be able to do much except provide Marco with the info he knows about the plague. Doctor to doctor talk.
5) Marco’s flames can heal. Fire/flame > Ice.
*Theory by Straw Hat Jedi / netanpc