It's often shown as a very intense and consuming force. Characters filled with this power might have a dark aura around them in the fanfiction. Their eyes could glow with a menacing look, signifying the 'Power of Hatred' within.
In Naruto fanfiction, the 'Power of Hatred' can often lead to characters making extreme decisions. For example, they might abandon their previous moral compasses. This power can fuel dark and powerful jutsus, as seen in some fanfics where characters like Sasuke are further influenced by hatred, causing him to be more ruthless in battle and his pursuit of power.
Naruto might also face hatred by becoming stronger. He trains harder and shows his opponents that he is not someone to be underestimated. For instance, if a group of rogue ninjas hates him because they think he's too idealistic, he proves them wrong by defeating them in combat and showing that his ideals are what make him strong.
In some fanfictions, Naruto's Six Paths Power is portrayed as having a darker side. Maybe it corrupts him a little, making his decisions more morally ambiguous. This is different from the original where he was always the hero with a clear moral compass.
Often, the Justice League's hatred for Batman in fanfiction is demonstrated by their actions. They might exclude him from important missions or decisions. For instance, they could form a subgroup within the league and intentionally leave Batman out, showing that they don't want him involved. This can also be seen in the way they interact with his ideas. They may quickly dismiss any suggestions he makes without proper consideration just because of their dislike for him. And sometimes, they may even plot against him in the fanfiction, trying to undermine his influence within the Justice League.
His thoughts are also used to portray his hatred. The author might write from Harry's perspective, and we can see his negative thoughts about people. He could be constantly thinking about how everyone is out for themselves or how no one really understands his pain, which then colors his view of everyone around him.
Their relationship could be shown as a source of strength. In the face of the new and dangerous situations in the Power Rangers' world, Naruto and Hinata would rely on each other. Naruto would be more protective of Hinata, and Hinata would be Naruto's calm and supportive partner. For example, when facing a powerful enemy, Naruto would charge forward while Hinata would use her Byakugan to analyze the situation and give Naruto advice.
Often through his internal thoughts. The fanfiction might describe Luke seething with anger whenever he thinks of Vader. For example, in some stories, when Luke is meditating, his thoughts are constantly interrupted by visions of Vader and his past actions, and he can't focus because of his hatred.
The way Sebastian interacts with other characters in relation to Ciel can also show his hatred. He could be overly critical of Ciel in front of others or even try to undermine Ciel's authority subtly.
In Naruto fanfiction, the Rinnegan in Naruto is often portrayed in really cool and powerful ways. Some fanfics might give Naruto the ability to use all the Rinnegan powers to their fullest extent right away, like being able to effortlessly summon the Gedo Statue or use the Deva Path powers without any drawbacks. It's a way for writers to explore new storylines and make Naruto even more of a badass than he already was in the original series.
In Naruto fanfiction, the concept of 'Naruto Demon' can be portrayed in various ways. Sometimes, Naruto might be depicted as having some sort of inner demon that he has to struggle with, like a dark side of his chakra or personality. It could also be that a demon is fused with Naruto in the fanfiction's alternate universe. This can lead to new powers and challenges for him as he tries to control or come to terms with this new aspect of himself.