In my comic, there's a war going on and one of my characters actually had the power to end it from the very beginning. But of course there's a philosophy involved. People must adapt through certain situations as they develop. Everyone wants whats best for Earth and/or it's inhabitants, but if the situation is cleared up with no lesson, no form of understanding then it's pointless. I have this theory that every war is a result of the circumstances following the last, regardless of size, ideals, or players involved. Circumstance and time is all anyone needs to see their world built and burned to the ground.
Everyone's power in my story comes from learning. Even if someone uses raw power, they either learn for the next encounter or there is no next encounter. Anyone in my comic can become the most powerful person in the universe but they need to learn both how to obtain said power, and how to use it effectively. Otherwise, they'd destroy themselves in the process.
Of course i have rules. Some i've decided are: No sentient character in my story can wield cosmic powers and no sentient character can be the smallest particle in the universe. Essentially this means that levels of power that rival the sun can not exist within a character's arsenal; wielding anything more will either destroy said person or that person will turn into the non-sentient essence relative to the power they tried to use. And when it comes to the smallest particle, no living thing with a mind can be that small. Anything that small has to rely on it's nature not it's non-existent mind. If anyone tries to get that small, they're brain activity will shrink with them. If someone wants to control something that small, that thing will have to be created with a predetermined purpose for it to follow. No direct or remote control, just purpose and nature.
Another rule: Regardless of how powerful you are, if a blow or blast strong enough to create a dent or hole in two inch steel hits you, whether that be from someone else or self inflicted, it can knock you out or kill you depending on where it hit you. It's like wearing a helmet. It can protect the outside but it ain't protecting anything on the inside if you get hit by a car. We're all squishy inside. Sure some characters are little more resilient than others but only a little, like a few extra pounds of force but that's it. This is where thinking on your feet becomes important in a fight of this caliber.
Essentially, even if my characters are super powered, they're still grounded in a relative sense of realism.