At the height of his power I'd say that nothing short of the Infinity Gauntlet could do it.
Even during Hickman's run we see one of the Reeds with an Infinity Gauntlet taking out three Celestials effortlessly after channeling power from its native universe.
So in-universe I think its power to control the universe would be above Franklin's.
Originally posted by Astner
At the height of his power I'd say that nothing short of the Infinity Gauntlet could do it.
It took the following to put down 4 Rogue Celestials :
a) A four planet fed Galactus
b) Sol's Anvil (without this they were all dead)
c) Adult Franklin Richards
d) All of child Franklin Richard's power (to revive Galactus)
Even at full power, any abstract worth it's name would wipe Franklin from existence. Hell, a Many Angled One like Shuma Gorath would destroy Franklin (see Thanos Imperative).
Originally posted by Magnon
Pretty much anyone who has damaging attacks and can take him by surprise. Unless he consciously protects himself, Franklin has normal human durability.So, lets say Forgetmenot with a gun.
When kid franklin confronted the mad celestials the exact opposite was implied. He unknowingly protected himself from the Celestial's attack.
Originally posted by zopzop
Uhm guys. He had no powers in that reality 😄
The inhibitors were gone at that point if that's what you mean. I'm pretty sure he wasn't powerless. He didn't even die in that instance, he was destroyed on a physical level only.