Fan Fiction: Ace Sanchez's Pokemon Master, an old but classic dark fan fiction with LOTS of violence, had one of the creepiest examples of this and/or a few others. Ash would, on at least three or four occassions, become the cold, emotionless assassin he used to be with Glowing Red Eyes, becomes incredibly stronger and MUCH faster, his battle lust kicks in as if he'd had his Berserk Button pressed but not actually going berserk himself per se (more frightening because he was in perfect control). It was revealed in the end that this was due to his alternate personality formed by a splitting of his soul into good and evil. He retainrf the skill in his good form because he was Just That Awesome, but when the other side took over he was like a demon and even went by the name Ashura (his assassin name) which is the name of an Indian or Hindu god of death.

The Avatar State is Super Mode - Not An Example of this trope!

Cleaned up one bit slightly. Poor phrasing made it look like the writer meant that higher-order thinking and morality were deemed "evil" by "Western Christianity".

Is there an opposite to Superpowered Evil Side? Like something being fueled by justice, rather than fueled by anger/revenge.

Is there such a thing as a Superpowered Well Intentioned Extremist Side?

Should there be?

On humans and chimps:

1. The chimp's forward limbs are the size equivalents of a human's legs, not arms, which is why they're so damn strong. This concentrates their dexterity and top strength into one limb (the dominant arm), something generally unavailable to humans. Even most obese people can easily stand on one leg, if they have good balance.

2. The human has a weight advantage of about a third or even more (disregarding the small size imposed on previous generations and various ethnicities even today by overpopulation and food scarcity; many people are indeed as small as chimps, though, because of the legs, not as short as the females), but it is largely spent in the large brain, the large digestive system it needs and the postural muscles, notably the massive Gluteus Maximus; human and common chimp ribcages are about the same size (not proportional). The rest of the advantage is offset by the fact that chimp muscles are still about 10% better by default - one of the very few creatures to trump us in that regard, by the way.

3. Humans are not taught to rely on personal strength for their safety - even soldiers and criminals use numbers, tactics and guns to substitute. This is why so few people can dedicate themselves to the kind of training that prepares one to savage one-on-one or few-on-few brawling: we've evolved away from that shenanigans. And those of us who do are still better at it than chimps.

4. Even the case of Travis the Chimp's 2009 attack was one of a truly massive male in the prime of life (Travis' age and size would translate to something like a 270 pound 30-year old man) attacking an old female not at all used to violence and mauling her, then taking an ineffective knife wound and finally being killed by gunshots. All the fuss behind it was really caused by the Squick induced by the chimp's tactic of mauling; humans prefer to only strike and grapple when not using weapons, to the point where we're shocked when someone or something decides to pull something else out of the bag. Men and women smaller than Travis' 200 pounds routinely do worse to their targets, either with no weapons or with the same crude ones that a chimp might use, though we tend to inflict either outright lethal wounds, or wounds that it is possible to at least partially recover from.