If there was a crossover between the 2 there would be the most OPcharacter in the history of anime. Now you might say that one punch hman would be stronger. But hes not. Even though the creators of one punch man
says that one punch man hasnt used a quater of his strength, he cant fly like dragon ball and cant do jutsus. Sure he might come up behind you but if you've mastered oarticle jutsu you have the win.
Particle jutsu is the jutsu of particles. You can make a blast as long as the great wall of china out of thin air. If you've mastered it then you can change youre shape and where you stand. You can also apply this to other jutsus like the rasengan.
If the character is a decendent of the goku or vegeta they are OP by themselves. You power up in the middle of a battle which makes your power greater than your enemy.
If the cross over perfects both...
We might have a winner.