Upon regular consumption of a form of entertainment, with intimate knowledge of understanding how it works & sincere enjoyment of said story/stories, the user of this Hatsu is able to mimic the learned power system of that particular form of entertainment if it has clearly defined rules (or at least practices), and have their own skill developed from it.

Example of what could be learned: Cursed Energy, Jutsu, Hamon, Stands, Dragon Ball's Ki, simple magic systems like in Charmed, Toon Force

Examples of what couldn't be learned: Kingdom Hearts, Final Fantasy, DnD, things directly tied to in-universe items like the Omnitrix transformations, things where the items ARE the magic systems like Death Note

Edit: Forgot restrictions. I'll add them.

1. You must sincerely enjoy the thing you consume for entertainment. Yes, you can be critical of aspects of it, but ultimately, you must enjoy the thing sincerely.

2. If you use these skills to violate someone's bodily autonomy without reasonable cause of saving lives or harming others in equal or lesser proportion to harm they deliberately caused, you will suffer a fate worse than death

3. You can only mimic the most recent media you have consumed a single full entry on. Meaning 1 issue of a comic, 1 chapter of a book, all parts of an episode, or some other similar value.

4. Leniency clause; you may use items you own to mimic a necessitated item within the in-universe power system, such as an official toy that mimics the conduit of power for in-universe usage