I'm glad that you're trying to balance this, but honestly... how is anyone fighting you supposed to get past nuclear flames, nuclear bolts, a DBZ inspired nuclear mode, C4, indestructible knives, only to kill you and find a nuclear warhead headed straight towards them (which level entire cities, and spread hundreds of miles worth of radioactive material) then have to scour through the wreckage, find you before you run off, then kill you AGAIN.

So what can you do? You've made a good start; the knives and C4 are pretty reasonable, but you really only need one minor ability to top that off, such as a suicide bomb that regenerates Nukboy and his indestructable knives (though not his fragile explosives) when Nukboy dies.