Guys, I made another unexpected discovery on Reddit ⊙_⊙
Its basically where Napoleon dies at Leipzig, and as a result there's no Hundred Days Campaign. Napoleon had managed to gain the upper hand in the battle and rode out to boost morale among his troops when he was hit by enemy fire. As a result of his death, the Army lost coalition and France's Empire came apart at the seams. A few loyalists tried crown Napoleon II as the new Emperor, but once the Coalition forces marched on Paris, Marie-Louise fled with her son to the Austrian Court. The Bourbons were restored with France keeping its pre-Revolution borders. France is in a much stronger position without the Hundred Days with the resources of the bits of the Rhineland it had, and the lack of a War Indemnity levied upon it after Napoleon's Hundred Days Campaign of OTL.
Napoleon II basically grows up in the Austrian Court but is fond of his father's legacy and resolves to have a career in the army. He also takes a deep interest in his education and tries to learn military strategy from whatever books he can. Napoleon grows bitter from the gilded cage that Austria has trapped him in, and develops a personal resentment towards Metternich. Napoleon manages to earn his grandfather's sympathy, and gains command of a battalion in Tyrol. The revolts against King Charles X of France occur like in otl but this time its a full blown Revolution. Though Bonapartist support among the old Napoleonic veterans and some segments of the French population is high after Napoleon's death in battle rather than him being defeated, and placed in exile. The Revolution of 1830 causes both the Bourbons and the Orleans family to flee. The liberals and moderates now have no one to rally to, and a self proclaimed Second Republic is declared in Paris. Though not everyone supports this as it brings back memories of the chaos and anarchy of the First Republic. Napoleon II arrives in France and the army defects to him en masse. He presents himself as a candidate restoring order in France. Napoleon then marches on Paris which is held by the unpopular Second Republic and easily takes the city. The Austrians reluctantly back him as he's Emperor Francis's Grandson. Napoleon then declares that he wishes to uphold the peace in Europe in order to assuage the fears of the rest of Europe.
What follows below is a possible long-term sketch of the TL, so I'm spoiling it in case you don't want to know what it might look like.
Edit: The Spoiler was removed if you want to know it at your own risk you can know it in the original link.
Original Link: //www.reddit.com/r/AlternateHistory/comments/e7rzu8/second_french_empire_and_its_satellite_states/ (place the typical https: at the beginning of the link in your URL search engine if you want to access)