Board Thread:Manga Discussion/@comment-189.84.202.137-20180524152410/@comment-26871105-20180628143450

Shalnark analysed Hisoka's remains on Chapter 357 and concluded that Hisoka's cause of death was a suffocation from the violent vacuum that formed by the explosion and the bodies that piled around Hisoka at the time, while Hisoka's body took relatively minor damage considering the scale of the explosion thanks to the bodies around him that formed a cushion.

As far as Hisoka's body is concerned,  Hisoka's injury from the explosion itself only mounts up to the loss of some of his skins above his chest, some of his facial features, as well as the loss of his right lower leg. This actually makes total sense, because Hisoka was curled up at the time right before he died, and it can be induced that the explosion that were the least cushioned blew up pretty close to face; this also explains the suffocation.

So that bit makes total sense.

What doesn't make sense is not that Hisoka is somehow undamaged enough to be revived from a CPR he performs on himself with his left-over Nen, but rather how his body is able to be revived despite the extended period of being actually dead.

A human brain starts dying at an exponential rate after 6 min or so without oxygen, and any recovery after that point will be faced with different degrees of permanent injury and functional impairment in the brain. If left for longer, organs in the body, especially the high-demand ones, start dying and become unrecoverable. After 10-15 minutes of cardiac arrest, with the sole exception of miracle and outliner examples, a body becomes impossible to be revived, because even if you somehow resume the oxygen supply in the body and keep everything pumping, the cells would be to frail to recover and they would all die anyway.

And since the arena has been fully evacuated and Hisoka's body has been moved into the changing room, possibly originally relocated for transportation by the ambulance crew who may have been knocked out or killed by the Troupe members that arrived to check on Hisoka's body, Hisoka has most likely been dead for over 10-15 min, which makes him impossible to revive even if his Nen managed to keep his heart and oxygen going as both his brain and organs would be too damaged then.

On that front, Hisoka's revival is not scientific, but NOT how he didn't get blown to smithereens.

But then again, who reads HxH as a science fiction? What's more, Togashi at least nails the science and other related details better than OP, so not sure why OP is complaining.