@Mitarashi, Actually it is still quite farfetched, even for Kishi's universe. I mean come on, the impact caused a tremor the can be felt literally hundreds of miles aways. Not even an nuke has such feats. The impact at ground zero is at least on the order of several hundred megatons. Yet Onoki has not, anywhere else, demonstrated any feats that would even suggest that he could do this. Does he have 3rd Raikage's armor? No. Does he possess steel release? No. Does he have a shell of chakra infused sand guarding him like Gaara? No. He took the impact with his own flesh, soft human flesh. Is there a reason that explains why young Obito lost half his body to a bolder nearly a trillion times lighter and yet Onoki didn't lose any limbs? Even Madara and Muu were blown to pieces, and they were further away than Onoki was. That is farfetched.
When did Sasuke actually touch his Enton? with his own hands?
I only recall him using Susanoo to hold the flames. Besides, those black flames are somewhat slow burning. It probably burned slow enough that Susanoo's automatic regeneration made it seem like it was nothing.