Well, they said, and I agree with them, that they’d only lock weapons to a subclass if it’s necessitated by lore, like Druchii repeaters being only available to a dark-elf-esque character.
Though then I wonder why Longbow is limited to Huntsman, besides the fact that it is obviously stronger than all other options - balancing, I suppose.
What is of course possible is a weapon that is most effective on a specific subclass - f.Ex. Mercenary taking a weapon with strong cleave values, or Repeater Crossbow being often used by BH because he gets more ammo and can use the triple shot crit.
In that vein, we could also have weapons for the unchained.
What remains a problem, however, is that sienna is balanced around Ranged.
If we want her as a legitimate melee option (and not just a ‘tank’-melee), we’d need a talent or trait that somehow makes her worse in that respect, or have a mechanic baked into the weapon that really emphasizes not scorching too many things from a distance. Or another subclass, if they ever get 1 more done per character, though I doubt it.
A 2h sword could be done relatively easily by elongating an existing flameword, and taking a mix of animations from the wardancer blade, her mace, and the existing flamesword (That 'spreading fire on the blade animation is pretty awesome). A combat staff would be even easier with a small model change on an existing staff and small animation modifications - it could handle like a halberd with a bit of mace or hammer thrown in, substituting fire for sharp tips. However, they are certainly not too creative options.
Similarly, a burning censer could just be based on Saltzpyre’s Flail, probably with the same animations given it’s actually of less weight, and then add a whole lot of burning and maybe modify the light attack partern.
This could be locked; wieding magical flame close to your body, all the time, is something no sane battle wizard would do.
What could work with unchained without just locking weapons would be to play around with inherent modifiers. Those could be hard to explain to players, but if we had, say, an additive reduction of weapon power compensated by higher base damage, her “power on overheat” passive would effectively be stronger with that weapon.
When it comes to Claws, I would lock them to unchained for the visuals; She already has armoured gloves, strikes with them with the flame sword, and has forearm covers; just infusing them with flame and blocking by crossing arms would be rather cool and work best with her current model.