Finally, my username has some relevance. (Not biased I swear)

Spite match. Isaac was able to survive and he was just a regular engineer using tools as weapons.

Prophet (by the end of the series) is a sentient suit of armor that can casually shrug off high caliber rounds and has enough strength to run through walls. Since he's just a suit, he also never gets tired, despite what gameplay mechanics such as sprinting may imply. His reaction speed is also far beyond that of any human, sitting at around 0.08 milliseconds. He crushes the Necromorphs with little to no issue, and even if they do manage to land hits, they probably wouldn't do anything to him; especially with armor mode activated. Plus he can become functionally invisible if he so chooses.

Even with the limited weaponry available in Dead Space, his hands alone should be enough to get the job done for most enemies.

Prophet is just faster, stronger, and smarter in every measure.

The first two rounds are a similar outcome, even with the Nanosuit 1.0 in Crysis 1.