Sirius would be in a state of panic at first. But then he would quickly gather his wits. He'd likely try to find out what caused the seizure, whether it was a spell, a potion, or something else entirely. He might also call for Remus or other trusted friends for assistance, as he wouldn't want to leave Harry alone in such a vulnerable state.
Sirius would probably be very worried and immediately try to help Harry. He might use some basic healing spells he knows.
In this fanfiction, the seizure could be part of a curse that was meant for Sirius but backfired on Harry. Harry starts seizing in front of Sirius, and Sirius is filled with guilt and determination to reverse the curse. He uses his knowledge of the wizarding world and his connections to search for a cure, all while taking care of Harry and keeping him safe from any potential threats.
As time goes on, Harry could start to explore what it means to 'please' Sirius. He might recall their past relationship, the things Sirius likes and dislikes, and try to use that knowledge to his advantage. He may also feel a sense of loyalty towards Sirius that, despite the odd circumstances, makes him more accepting of the situation. For example, he might remember Sirius' love for adventure and try to engage in some magical adventures with him in a way that 'pleases' him.
Snape might initially be suspicious. He has always had a distrust of Harry, so he could think it's some sort of trick. But then, as a Potions master and a teacher, he might also feel a sense of responsibility and try to help.
Sirius would probably be overjoyed at first. Harry is his godson and he cares deeply for him.
Sirius might immediately pull Harry into a tight hug. He would be very protective and try to comfort him. He might say some soothing words like 'It's all right, Harry. I'm here for you.'
Sirius Black was a character in the Harry Potter series of novels by British author J.K. Rowling. He was the last heir of the Black family. He was a Gryffindor student, nicknamed Padfoot. He was tall, dark-haired, and handsome in his youth. He first appeared in Harry Potter and the Sorcerer's Stone as a close friend of the Potters and a member of the Order of the Phoenix. He was mistakenly believed to be a traitor and imprisoned in Azkaban, but he was actually James Potter's best friend and Harry Potter's godfather. In Harry Potter and the Prisoner of Azkaban, he was falsely accused of being a traitor and mistaken for Peter Pettigrew's scapegoat. He successfully escaped from prison, but was forbidden from entering Hogwarts and could only help Harry outside the school. In Harry Potter and the Order of the Phoenix, he was killed by Bellatrix Lestrange's Reaper Curse, but in Harry Potter and the Deathly Hallows, he was mysteriously "reborn" to help Harry defeat Voldemort. Sirius had the good character of sensing love. He loved James like a brother and extended this love to Harry. He was brave, loyal, fearless, and rebellious. He was deeply loved by readers. But he was also prone to impulsiveness, which led him to make some unwise moves, such as acting aggressively and recklessly when he was eager to get revenge on Pettigrew, going on reckless night walks with Lupin, teasing Snape when he "suggested" Snape into the Shrieking Shack, which almost led to tragedy, persuading the Potters to let Peter be the Secret Keeper, and being rude to Kreacher, the house-elf. When he was a teenager, he ran away from home. He left home at the age of 16 and did not have to worry about money because he had an uncle's sponsorship. He was captured and sent to Azkaban at the age of 22. Harry Potter and the Order of the Phoenix is not enough. Please click to read the novel!
The 'Harry Potter' books are set in a magical world full of its own stories, prophecies, and secrets. Sirius is a complex character with a lot on his plate. He has to deal with his family history, his time in Azkaban, and his loyalty to his friends. Fanfiction is a form of creative writing by fans outside the original story. Sirius doesn't have the time or the inclination within the context of the story to be reading fanfiction. His life is too filled with real magical drama and danger.
Harry might be initially shocked. He could feel a mix of sadness and a sense of responsibility. After all, Sirius was like a father figure to him.
He might be extremely hurt and confused. Harry has always seen Sirius as a sort of father figure, so being disowned would be like a huge blow to his emotional stability. He could become withdrawn and start to question his own self - worth.
Harry may also feel a sense of adventure. Despite the situation, he's used to facing strange and dangerous things. He might start to think about how he can use this situation to his advantage, like finding out more about his parents or the secrets of the wizarding world that Sirius might know. He could be a bit excited as well as scared. For example, he might be thinking that this could be a chance to get away from the Dursleys for good.