In these fanfics, usually a magical spell or some sort of arcane ritual summons Harry as a partner. For example, a powerful wizard might cast a spell to bring Harry to their side for a specific mission.
Well, the trope begins with the summoning event. This can be a very dramatic moment in the fanfic. After Harry is summoned as a partner, the relationship between him and the summoner or the group he is now part of starts to develop. Sometimes, there are power dynamics at play. If Harry is summoned by a more powerful wizard, he might initially be in a subservient position. However, as the story progresses, he often proves his worth and changes the power balance. Also, the reason for the summoning can drive the plot forward, whether it's to fight a dark force or to solve a mystery.
One popular 'Harry Summoned as a Partner' fanfic might be 'The Chosen Bond'. It often features an interesting take on how Harry is summoned and the adventures that follow. Another could be 'Summoned to a New Destiny' which delves into the relationship between Harry and his new partner in a unique way. There are also many others on various fanfic platforms.
Another way the 'Harry Potter is summoned' concept works is when a magical being with great power summons him. This could be a powerful wizard from another land or a magical creature like a phoenix or a centaur. They might summon Harry because they sense his unique magic or because they believe he has the ability to solve a problem that they can't. For example, a centaur might summon Harry to help deal with a dark magic that is corrupting the forest it guards.
Typically, in fanfiction, the forced bond between Harry and Draco is often magically imposed. It could be the result of a dark magic spell gone wrong or a powerful magical artifact. For example, a cursed necklace that once put on, binds them together in some way. This bond then forces them to experience each other's emotions, thoughts, or physical sensations.
The 'secret baby' trope usually starts with a character, often the mother, keeping the baby's existence a secret from someone, like the father. This creates instant conflict.
The 'Hermione is collared' trope in fanfiction works in multiple ways. Firstly, it can be a physical symbol of her being controlled or restricted, which might be related to a dark magic plot or a powerful enemy. For example, the collar could limit her magic or her freedom of movement. Secondly, it can also be a metaphor for her being bound by certain rules or expectations within the fanfic's created world. It can lead to interesting power dynamics, like she has to rely on others to help her remove the collar, or she has to find her own inner strength to break free.
The yandere in Spider Man fanfiction typically has an unhinged fixation on Spider Man. This can be shown in different ways. For example, they could be jealous of anyone who gets close to Spider Man, whether it's Mary Jane or his other friends. They might try to isolate Spider Man from his support network, believing that they are the only one who should be in his life. This often leads to conflict and drama in the story.
In otome game novels, the yandere trope often involves a character showing extreme love and possessiveness. For example, a yandere character might become jealous very easily and take extreme actions to keep the protagonist to themselves. They can be overly affectionate one moment and then turn menacing if they feel their love is being threatened.
In some Harry Potter fanfics, 'Turning Time' might work through the use of time - turners. These magical devices allow the user to go back in time for a limited period, like Hermione did in the original series to attend multiple classes. But in fanfics, authors might expand on their capabilities, such as being able to travel further back or having fewer restrictions on their use.
In fanfics, the concept of 'Harry uses chakra' usually involves some kind of crossover or discovery. Maybe Harry discovers an ancient magic that has elements of chakra in it. He then has to learn how to control and use this new power source. He might start with simple exercises like gathering chakra in his body and then progress to using it in combat or for other magical tasks.
In many fanfics, priori incantatem works in a similar way as in the books. It shows the last spells cast by a wand. But some fanfics might add extra elements. For example, in some, it can be used to reverse the last spell completely. Or it could be used to unlock hidden magical powers within a wizard if they can master the energy released during the priori incantatem effect.