Overpowered characters are those who have broken powers and are stronger than those of their level. When they are good guys they are empowerment fantasy, when they are bad guys they are an ever-present threat. Either way, the fundamental problem of an OP character is lack of engagement. They become boring very fast, if there is no challenge and they easily win no matter the situation. 

The obvious solution to this problem would be to introduce something that can defeat him. Which by way it is possible since Overpowered is not the same as Undefeatable. An overpowered character can still lose, just not as easily as others who share the same abilities or experience. Meaning, he is better than all his peers, but not above everyone in existence. It’s an unfair advantage and not an automatic victory. 

Having higher tier opponents though is not a limitation. Losing in battle by a much more powerful opponent does not somehow limit overpowered skills. The character is still broken compared to others who share his experience and he’s still going to be someone who levels up faster than the rest. In fact, higher tier opponents make his broken powers more obvious and thus magnify how boring a challenge is if it’s not unfair. 

Something else which many consider a limitation although it’s not is moral beliefs. Things that a character would never agree to do because they contradict his ideals. A classic example is for a hero to never kill his enemies, which often means they keep coming back and keep causing more destruction. A similar case is when a hero chooses to prioritize the rescue of civilians over defeating the bad guy, which results in the bad guy having enough time to harm more civilians. 

As limiting as that sounds, it’s also what prevents a hero from becoming what he fights against. Moral beliefs offer integrity to your status and a clear separation from whatever you do not wish to become. They are establishing what someone is, instead of letting someone become a mindless force of destruction that arbitrarily does whatever it feels like doing at the moment.              

An actual way to limit overpowered characters is something physical they are weak against, such as kryptonite for Superman. But even that becomes boring after awhile since it still comes down to every opponent somehow using the same specific trinket, or losing.

A different type of limitation is low intelligence. The character could be physically undefeatable but also incapable to think reasonably, which results in making mistakes and never achieving a perfect victory. It’s simple but works. 

A more interesting limitation is phobias. The character could be physically undefeatable but not mentally, since there are many things he would be afraid of, such as Mum-ra and his reflection, or Storm and narrow spaces. Unlike the trinket, there are many different ways for a phobia to trigger, even accidentally, which lowers the odds of an overpowered character winning all the time, without feeling that repetitive. 

Another fake limitation is victimizing. They make it seem like an overpowered protagonist is a tragic figure because everybody hates or is jealous of him. This doesn’t make it harder for the character to win. Nobody sabotages him in what he is doing, he just doesn’t get the credit he deserves after it’s all over. 

Down to it, there is no such thing as a good OP character, and if you truly want to have a compelling character with weaknesses, moral beliefs, and drama, you don’t make him OP. And if you so much want to have an OP character regardless of all that, you make him unapologetic and pure cheesy fun.

https://www.youtube.com/watch?v=WA9o__eEFDs