If an individual registers an LLC or S Corp in a country with lenient copyright laws and lives in a country that takes copyright more seriously, which country has jurisdiction over that individual - the country where the LLC is registered or the country where the person lives? Or both?
To answer the last part of the question:
Jurisdiction would be where the copied media is being producted and where it is being consumed/sold. Moving media from one jurisdiction with ineffectual protections to another jurisdiction is part of product piracy. The scheme you suggest might shield the company producing the counterfeit goods, leaving the importers holding the bag. If the importers and manufacturers are controlled by the same person, courts in jurisdictions with strong protection might hold that person liable for the whole criminal enterprise.
There is a widespread assumption that the internet is 'beyond national laws.' That is wrong. Enforcement may be difficult in some cases, but the laws apply. If you try to make profits by skirting the edges of law, you need really good, really professional legal advice.
The copyright laws of different countries have different exceptions, and different formulae for determining damages. Different countries also have different enforcement mechanisms, and different procedures for bringing copyright infringement suits. They may also have different terms. I do not think it is useful to ask which is "more lenient" because one may favor copyright holders in one way, but another may favor holders in a different way. There is not a linear scale from most lenient to strictest.
A copyright owner may sue in any jurisdiction where the copyright has been infringed. It need not be the place where the owner (whether a natural person or some sort of organization or corporation or other entity) lives, does business, or is registered. Nor need it be where the alleged infringer lives or does business. Any jurisdiction where an unauthorized copy is made, or sold, or other acts of infringement occur may be the place where a suit is filed, subject to whatever the local laws require. Procedures will be governed by the law of the place where suit is brought.
A work posted on an internet forum without permission may be grounds for a suit in any country where copies are downloaded or further copies are made. This might well be just about any country in the world. Jurisdiction is over the act of infringement, not over the owner or the alleged infringer.
However, it is often convenient to bring suit where the infringer does business and has assets that can be seized if a judgement is granted. It may in other ways be convenient to bring suit where the owner is located. A Plaintiff chooses where to bring suit.