Speculations The Gum Gum fruit was supposed to be a counter to Whitebeard

[Monkey D Theories]

Well i believe gomu2 will be vegapunk next project seeing that he can implement kizaru laser into a weapon, maybe gomu2 can make a rubber ship or armor which can withstand gura2 attack

This is probably the most likely answer

Vegapunk might have used the gomu gomu no mi to generate some sort of super polymer. Perhaps to create a raid suit of his own.

 

[Dr_Professor83]

lmao he's literally coughing up blood

Eating an attack from a legend like Sengoku and only coughing up blood is pretty good for pre TS.

 

[zzShinichi]

Kinda make sense, and Luffy is the perfect counter for Blackbeard

 

[WesMidnight]

If you can turn the air into rubber that can become extremely OP.

Not just against the gura gura, but he could bounce back Magma fists and other logia attacks over wide scale area like a trampoline and make Akainu accidentally destroy marineford.

It has the potential to basically be an offensive version of the barrier fruit if taken to it's extremes.

 

[Finalbeta]

Real life physics are not Oda's strong fit in the series therefore even rubber can become extensively lethal here, even more lethal than any elemental force of nature perhaps.

 

[Hades]

but this doesn't make sense

Luffy wasn't immune to roku o gan
he wasn't immune to fishman karate
And I don't believe he was immune to Chinjao's shockwaves either

I think shockwaves can still hurt him

Maybe in awakening form, it does....

 

[Date]

Hope is this, and with this Oda will already build up to the time when Luffy get to use it to counter Teach.

 

[Fn Lucci]

I don't see it. I mean for one I don't understand why they wouldn't have someone eat it.

Lmao.

Luffy was fine afterwards.

This is decently close to a hint actually. Sengoku reacts in a way that hints to some things, I doubt it myself but maybe he's incredulous here for a reason?

 

[Herrera95]

Too bad WB DF works on others while Luffy DF works only on himself. Maybe this could justify the asspulling of Luffy not receiving damage from Gura Gura no Mi when fighting BlackBeard.