TheVaultDweller
Front line cannon fodder
The FF from those movies were actually quite powerful (unlike the really shitty reboot characters we got last year), and Johnny got all their powers together.
So the invisibility + forcefields, which were powerful enough to contain Torch's nova flames.
Reed's elasticity, which allowed him to take all kinds of hits (including being squashed completely flat) without any actual damage, expand himself like a giant parachute, and even squeeze limbs through gaps in doors etc.
Thing's strength, which could press the London Eye from shoulder to over head height. Plus his durability, which allowed him to tank falls from several stories up, a spinning helicopter tail rotor blade to the face, getting rammed by a speeding truck, and having a huge, multi-ton steel door smash into him at high velocity, all without any actual injury. The only reaction he made to any of those was saying "Ow", when the door hit him.
And then on top of that, Torch's heat, which can go into the thousands of degrees celsius, plus flight speed that allowed him to keep up with the Surfer.
Combined Johnny is no joke.