I was looking through the tags, and I'm glad I'm not the only one who thought about Neyllington!!
Here's the AU for anyone interested (I won't go into too much detail for now).
The aftermath of Waterloo.
Ney has come to terms with his fate a long time ago. And now he's sitting in prison, waiting to be executed in a few hours. But then an unexpected visitor arrives.
Wellington, dressed formally and looking as businesslike as ever. Surely he has his own business here, but he probably came to mock him while he was at it, Ney thinks. He doesn't know that Wellington has actually come to ask the King to pardon the Marshal and to take him for himself...
In this AU, Wellington is a little crazy and obsessed (but in a relatively reasonable way🤔). He's like a hunter of extremely rare predators: the stronger his opponent, the more valuable they are to him. And Ney caught his attention at Waterloo, despite the circumstances.
Wellington would sit in his office, looking at Marshal Ney's baton, which he had taken as a trophy, and find himself unwilling to let such an interesting man be executed. And there weren't many people he could call interesting.
Especially since, after Waterloo, Wellington had to remain in Paris for several years after being appointed commander of the multinational army of occupation here. Its task is to prevent a resurgence of French aggression and finally give their useless king a chance to consolidate his power in the country. Wellington argued that having Ney as his aide would make controlling the French much easier.
Naturally, Ney knows nothing about this yet. And when he's baffled by the cancellation of his execution and finds out the reason behind it, he'd actually prefer execution.
But that's Wellington's decision to make now.