Just realized something important about undertale, that can drastically drop characters of undertale.
1: We say that the Undertale characters are really powerful. With characters like Omega Flowey, Asriel and Chara, that's definitely true. With other characters, not so much. Reason? Every battle is despicted as between 2 or more souls. Thus, they aren't attacks of truely physical feats; the battles are being fought on a spiritual term. That's why when Frisk dies, it shows his heart breaking, and not Frisk dropping dead. In fact, the only one monster with actual physical feats (I think) would be Undyne, in the pacifist ending. In that one, she cracks concrete out of laughter and slapping the ground under her. So while her physical feats may be justified, others aren't. Yes, the monsters are spirtually powerful, especially considering their HP, but for physical offense it's not the same.
2: Basically, fighting Frisk possesed by Chara might not count for an offensive feat. Consider this: almost all monsters have the same stats in pacifist and genocide route, bar Undyne as Undying, right? And given the chance, those same monsters can hurt Frisk and Chara-possesed Frisk for the same amount, right? If that's the case, then everything in undertale is overpowered just on the basis that they can hurt the chara possessed frisk. And in that case, Frisk on pacifist would be obliterated by such power, which isn't true.
3: Chara possessing Frisk is NOT the same as just Chara by himself. 1v1, I believe that Chara at full power would obliterate sans and Undyne the Undying in one shot, even with their hax. The reason that Chara possessing Frisk doesn't do so is because 1: Chara isn't fully awakened, and 2: Chara is being channeled through Frisk. Let me explain.
As frisk slaughters more monsters, he grows in power. As Chara explains in the end of Genocide, the more Frisk kills, the more Chara came to possess Frisk. As a result, Frisk grew in power exponentially, growing from tens of damage to hundreds and eventually thousands and millions. We know that Chara isn't fully awakened when Frisk fights Undying Undyne and Sans, because they still grow in power after killing the two (sans may not be dead after his fight, that's speculation). Aaand when Chara comes back in full, he destroys the world/universe (so the player is left to believe, which I am skeptical of). And yeah, destroying a world/universe takes more power than just enough to kill Undying, right?
Chara described himself as the feeling of grinding in a game (basically). He seperates himself from being just an evil ghost, and he is channelling his power across several timelines, to various Frisks. This would be akin to a God channeling his power into a avatar or some other being. Thus, it may be said that Undyne and Sans aren't fighting Chara himself (who slaughters planets/universes in the blink of an eye), but rather a fragment of Chara. Chara's possession may be considered a rift, being opened more every time Frisk kills.
Considering what happened above before, someone (probably Azathoth) will probably tear my theory/statement to shreds. But hey, we all learn from contributions, right?
