Sometimes it's the result of a large corporation's secret project. Big companies with unlimited resources and a thirst for power might create such an AI to gain an edge in the market or to control the world's information, as seen in many cyberpunk novels.
One characteristic could be super - intelligence. It can process vast amounts of data instantly and come up with solutions to complex problems that humans can't easily solve. For example, in some fictions, it can predict future events accurately based on minute details of the present.
One of the most powerful characters in fiction is Superman. He has super strength, can fly, has heat vision and is nearly invulnerable. He can move planets and survive in space, which makes him extremely powerful in the fictional world.
I don't know who specifically creates 'eddie fiction'. It could be a person named Eddie, as the name implies.
I don't know for sure who creates'saradas fiction'. It could be an individual named Sarada who writes these fictional works.
One possible powerful jutsu he could create is a time - freezing jutsu. This would allow Naruto to stop his opponents in their tracks, giving him the opportunity to either land a decisive blow or set up a more complex strategy. Since Naruto has always been about speed and surprise, this jutsu would add another dimension to his combat style.
Some of the most powerful fictional beings are the Q Continuum from 'Star Trek'. The Q are omnipotent and can manipulate time, space, and reality at will. In the world of Japanese anime, Goku from 'Dragon Ball Z' is also very powerful. His power levels keep increasing throughout the series and he can perform incredible feats of strength and energy projection. Another is Lucifer Morningstar from the 'Sandman' series. He is an extremely powerful fallen angel with a vast array of powers.
A popular powerful dragon in fiction is Toothless from 'How to Train Your Dragon'. Despite his small size compared to some others, he has the ability to shoot plasma blasts, is extremely fast and agile, and has a very close bond with Hiccup which gives him an edge in battles.
In the 'Dragon Ball' series, Zeno is an extremely powerful being. He can destroy entire universes with just a thought. He is the king of all the universes in the Dragon Ball multiverse. His power level is so high that no other character can really compare to him in terms of sheer destructive capacity. And his decisions are absolute, which shows his dominant position in the Dragon Ball fictional world.
One of the most powerful vampires in fiction is Dracula. He has superhuman strength, the ability to transform into various forms like a bat or wolf, and can control the minds of others. His immortality also gives him an edge, having lived for centuries and accumulated a vast amount of knowledge and power over time.
Galactus from the Marvel Universe is also a very powerful figure in fiction. He consumes planets to sustain his energy. He is so powerful that entire civilizations tremble at the thought of his arrival. His powers are on a cosmic scale, and he has abilities that far exceed most beings in the Marvel Universe.