why after lützen (efter lützen) is a promising ficseries

 You already know from El semen de los ahorcados that Courfeyrac had an ancestor who fought in the Thirty Years' War (and whom he dressed up as for a masquerade). Well, his story is about to be expanded upon, as a StrixAlluka 30YW AU with the Amis as Swedish Army deserters turned guerrilla soldiers of fortune is underway. It will be in Swedish and called "Efter Lützen". Enj is Prussian landed gentry and R a Moor by way of Marseille (Schönherr Engelhart and Razi/Remi)... most of the cast will remain French though with a few more exceptions (Musichetta, Leslie - Lesgle, Joellll - Jolllly)... Furthermore, Gustavus Adolphus will play the role Napoleon played in canon Les Mis!

The idea or bunny came partly from that reference to the musketeer Baron de Courfeyrac in El semen, partly from a mention of Lützen in Les Misérables canon, Colonel Pontmercy having fought in the Napoleonic battle. But I could not shake the idea of the 30YW battle off my head and wondered what if Les Mis had been set in that period and all the Amis sans Marius had been killed in that seventeenth-century war. And of course Colonel Pontmercy would have fought in a Swedish-French alliance and been killed at Lützen...

Schönherr Engelhart and Jules Combeferre + Hercule de Courfeyrac. There you have the rittmeister and his two lieutenants respectively, who keep the ranks they held in the Swedish military. The young Prussian of the landed gentry and his French teacher's son, who has a plan to sort out all flora and fauna a century before Linnaeus, both joined the Swedish military in their late adolescence in order to fight for freedom of worship. The young Gascon baron and lieutenant of musketeers came to the heart of Europe as an envoy to the Swedish camp, representing the Cardinal (Richelieu), with a certain Moor by way of Marseille (R, aka Razi, aka Remi) for a valet (and cupbearer, and squire...).

Razi (Remi), the Moor who never has laid eyes on his parents' birthplace of Castellón, started out with his widowed mother Miriam (Marie) on the docks of Marseille; her husband having been killed in a street fight on those same docks. He became a petty servant in Courfeyrac's entourage thanks to circumstances beyond his control

The Álvarez (actually Thénardier) family - camp followers, confidence tricksters, and corpse plunderers, whose wagon home can always be found when an engagement has just taken place. Cosette's former guardians, who pretend to be Spanish nobles (according to the Thénardiers themselves, he's from Barcelona ---Fawlty Towers reference!--- and she's from Santiago de Compostela). Éponine alone, their firstborn, is not supporting this elaborate confidence trick; unlike her younger siblings Azelma and Gavroche - although the latter joins Engelhart's company alongside his eldest sister, as per canon

Cosette, Marius, and Valjean "the snowy owl..." Innocent orphan adolescent Fantine was, in this era, ravaged by a thirtyish officer when her home village was raided; she entrusted her daughter to the Thénardiers just like in canon for the same reasons and became a worker in a uniform cloth factory in Wallenstein's province of Friedland, with Valjean for an overseer - his backstory is also just like in canon (older sister and fatherless nephews, bread theft, prisoner camp... lock stock and barrel - only sans kindly bishop and with Wallenstein instead).

Musichetta - here she is a North Italian (Ferrarese) opera singer who was soubrette until a while ago to fairytale collector and primadonna her southern friend Adriana Basile (who compiled the Pentamerone alongside her brother Giambattista!). Not long ago they parted ways when she decided to move up north into the war torn heart of Europe with the half of the company that preferred opera buffa to opera seria - in order to bring smiles to the regions with commedia-dell'arte style plots and gags.