Marco's performance against Big Mom here isn't anything that surprising when you look back at MF. His regenerating flames allowed him to completely block Akainu's magma punches and also no sell Kizaru's light attacks, tanking them without issue and literally charging through his barrage of beams to end up right in his face. Difference here is that Akainu and Kizaru are logia and thus their elemental attacks have practically no limits while BM's elemental attacks rely on soul energy which we know can be exhausted.
The thing is that those elemental attacks are just one part of BM's tool set. Her physical strength and haki are great enough to stop G4 attacks without trouble. She was seemingly able to go up against Kaido in a purely physical fight for several days, the same Kaido who put Luffy out of comission in a single blow and just this chapter, she was able to physically overwhelm Marco by straight up grabbing him and putting him at the mercy of whatever blow she wanted to follow up with. Marco's regeneration also has limits as Oda said and as we saw from his state after the battle of MF, which lasted hours at most.
So yeah, Marco can definitely last in a fight against BM same as he can against the admirals. But actually damaging her and being an actual threat is something he has yet to show.
The thing is that those elemental attacks are just one part of BM's tool set. Her physical strength and haki are great enough to stop G4 attacks without trouble. She was seemingly able to go up against Kaido in a purely physical fight for several days, the same Kaido who put Luffy out of comission in a single blow and just this chapter, she was able to physically overwhelm Marco by straight up grabbing him and putting him at the mercy of whatever blow she wanted to follow up with. Marco's regeneration also has limits as Oda said and as we saw from his state after the battle of MF, which lasted hours at most.
So yeah, Marco can definitely last in a fight against BM same as he can against the admirals. But actually damaging her and being an actual threat is something he has yet to show.
