Well, here my longshot for Sienna’s new career. From the available U5 careers Sienna is the most difficult concerning a new career. Most people would probably like to see a new wind.
However, Human Wizards can simply not learn more than one wind without going crazy (and that is formulated politely). This can also not simply overlooked by saying that she will just perform one wind. Knowledge alone is enough to make even the steadfestest human go mad. Then again, the Endtimes were kinda crazy for Wizards and we had Divine Intervention before (GK, Shade, Handmaiden) in order for some advanced Lorebending. There would still be issues with a new wind for Sienna mostly because fire is kinda her thingy AND because so far we have only seen two new weapons per career. And a new wind would mean a complete overhaul of said arsenal, even if it would be reduced to visuals only (like giving her Azyr and coloring everything blue).
With this said, here comes my personal guess:
Maiden of the Blazing Sun / Female Knight of the Blazing Sun
I will not go into details as how this will play out because I am to lazy to imagine how a new career might work. But I will go a bit into why I consider this a viable suggestion.
So far GK and Engineer had both a “Back to the roots” thematic attached to them. For Kruber it was his Bretonnian ancestry (he didn’t even know himself) and Bardin it was an old wish (being an Engineer Apprentice) he never came around to fulfill.
What would back to the roots mean for Sienna? Sienna is a native Estelian from where she slowly travelled to Altdorf. Equally native to Estelia (or Tilea) is also the human goddess of war: Myrmida who united the southern civilizations. And worshipping Myrmidia is the Order of the Blazing Sun. Why would the order be a good fit for Sienna?
- Many of their weapons blaze with a bright and fiery power, enchanted with the divine flames of their goddess.
The order uses weapons enchanted with divine flames. Sienna’s whole melee arsenal could stay the same. She just would have to “pledge” her flame to the goddess Myrmida or even exchange her magical fire for divine fire.
- These fervent followers of Myrmidia value ability and accomplishment over all other factors, including noble birth and their prowess in battle
The Order is not picky about their members. They don’t have to be of noble birth. They just need to have ability and prowess in battle (and some minor sidestuff).
- Unlike most other Templar Orders, its members do not reside in large chapter houses; instead they travel the land individually or in small groups, looking for new challenges to test their skills and lend their aid to the poor and defenceless
They do not insist on some kind of army formations. They are known for being loners or working in small groups. And helping the defenseless is something Sienna has done during her fights in Ubersreik and Helmgart.
- The knights spend a great deal of time training in rather unusual methods of warfare, unafraid to experiment with ploys, tactics, and equipment other Knightly Orders might overlook or find dishonourable. Many of these Knights are even well-trained archers, a result which lead to the formation of the Knights of the Verdant Field. Some of the knights have even been known to use highly burnished shields, employed to dazzle the knights’ opponents with reflected sunlight and strike while they’re blind.
A Knight using the wind of Aqshy might seem absurd. However, the Order of the Blazing Sun is known for using unusual methods of warfare. So even as Knight, Sienna could still use her staves. So her ranged weapons could also stay the same. Her knighthood and the divine flames might even enable her to get some new ranged weapons imbued with fire magic like … no idea what Estelian weapons are.