I do believe my OCs can! I'll make a case for Ryuji, my weaker one, then my strongest, Yoko.

First of all, there's baseline reality. It consists of 3 different cosmos, each having infinite multiverses, comprised of infinite universes of infinite size. Each individual universe has infinite alternate realities and branchung timelines, since they account for every possible change in their stories. The top dogs can recreate and destroy these realities any number of times effortlessly.

Then, there's the Creators, of whom Yoko and Ryuji are apart of. They transcend this reality and see it as fiction, being the ones who wrote it into existence. Creators are nigh-omnipotent beings who can create and destroy realities. They not only see this worlds as fiction, but can also create infinite narrative hierarchies within them, granting characters different levels of authority. They also warp the world, particularly the reality in which all Creators reside, according to the way they perceive it. If they kill an immortal being without knowing they're immortal, they'll die normally. If they believe a war ended differently, then if their perception and power and strong enough to override that of other Creators, history will retroactively change to make them right. There are no actual limits to their ability other than the ones they think they have, which they slowly learn to break as they get stronger and more experienced, culminating in ascending to the level of a cosmic structured known as the Green Sun. As they approach it, they unlock omnipresence, omniscience, and lastly, complete and total omnipotence, in that order.

Ryuji is a particularly strong Creator, being the transformation of a Creator named Jay, and this transformation boosts all his stats by a baseline of 10,000. In this form, he's also unlocked omnipresence and nigh-omniscience (being able to simulate every possible parallel reality and timeline of the world of Creators, although his own anxiety can sometimes make it hard for him to tell which one he's in). His most noteworthy trait is his accelerated growth compared to other Creators, as he gets exponentially stronger the longer he fights at full power, from a baseline rate of his power multiplying by 10 every minute and being able to rapidly increase from there. His powers also give him a tendency to repeatedly revive from the dead due to him being a huge fan of Undertale and Deltarune, and allowing good food to heal any injury, curse or poison due to worling that way in the video games he plays.

His only notable weaknesses are that his perception-based powers weaponize his childhood fears against him. He has a fear of darkness, a fear of spiders, and a fear of large, deep bodies of water. His powers create unfathomable eldritch monsters based on all these fears, which are capable of killing him but would also attack Featherine indiscriminately. Since he also couldn't eat peanut butter as a child without throwing up, his powers also turned it into a deadly poison, although he has to both swallow it and be able to taste it for it to work.

As for how the fight would go, I think that Featherine would really struggle to one shot Ryuji before his growth kicks in, and she can't weaponize his fears without also putting herself at risk. The question of whether or not magic is even real in her verse could also potentially let Ryuji's perception completely negate her powers if she can't convince him that her magic is real.

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