About the AUEdit
In this AU, the members of the Big Four are portrayed as the three/four Musketeers as they keep the King/Queen and the streets of Paris safe and keep to the code: All for One and One for All.
From hearing the King's guards tales and watched them train from the church, Hiccup left to work at a forge; so he can see them do their work close up and to forge swords for them. Once the musketeer order fell and overheard a plan to take out the King while working, Hiccup started to make weapons in secret, with tweaks and touches as he and two others kept the peace.
Hiccup's leadership casts him as Athos, while his looks, loves to read and doesn't take joy in taking lives gives him the role of Aramis. He can also be cast as young d'Artagnan, with the musketeer dream.
Before the Musketeers were dismissed Jack played cards with them in trade for stories and lessons and he uses his card skills, getting people to slip information and his way with women help him learn and gain the Cardinal's secrets, targets and obtain their gear. Like new weapons and trophies, like old musketeer robs.
Jack can be cast between Porthos and Aramis. He can also play the role of d'Artagnan, the newest member of the musketeers; much like how he was the newest member of the Guardians.
The King's daughter or a young princess staying in Paris as a sigh of peace and trust watched and befriended the king's guards as she learned their skills and code. Merida blames herself for the musketeers dismissal, as she was the one who told them about the Cardinal's plans for Frunze and the guards that tried to stop him and warn the King were killed. So she dressed herself up as a man and placed a mask over her face as she and two young men fight the Cardinal's guards and undo their deeds. The mask hides her identity while she keeps the peace on the streets and spies within the castle's walls.
This casts her as the leader, Athos.
Leaving home for the first time to become a musketeer in Paris, like her father before her was hard for a girl from the contrary and it got harder when she learned about the guards dismissal. She was about to turn back, but the whispers of three young masked musketeers keeping the code alive brought her hope, so she set off to find them. The three weren't sure of her at first, but after seeing her sword skills they take her on as a musketeer in-training and the princess's lady in waiting. The leader needed someone with her in the castle and to watch her back from the Cardinal and his guards.
This casts her with the role of a female d'Artagnan or his lover, Constance Bonacieux. The kingdom of Corona can serve or be used as the city of Paris.