I'd like to know exactly how much we could genetically engineer a human to be able to withstand any serious hit by a blunt object, a knife or sword slash, or a gun shot. Doing this with things like extremely hardened skin or bones, extremely fast regeneration abilities and things that would be possible with genetic engineering is my goal.
My guess is that it may be possible to make him almost immune to blunt objects and slashes, but I am seriously doubtful about gun shots, and things like missiles or atomic bombs would be totally out of place.
For the answer I am considering anything valid in theory, even if it has not been possible to implement it yet IRL.
Basically, what I am asking is: How would it be possible to generate a completely biological human reasonably resistant to conventional, chemical and biological weapons?