I’ve always thought the Rogue could use more Cold support, especially because the Vial of Volatile Ice is so cool. But there’s no real support for frost beyond that.
While there are some neat cold swords (Yrun’s Penance and Apogee of Frozen Light come to mind) they aren’t really set up to do anything to help the Rogue. What I’d really like to see is a Dagger that works similarly to a mashup between Troaka’s Teeth, which converts Poison and Bleed on Puncture to Frostbite, and a cold version of the Fulgurite Shard which is essentially required for any Lightning Bladedancer builds. For this, I’d mostly love to see it target Flurry.
Partially because I think Melee Flurry is a cool skill in general (and is rarely ever used) and admittedly partially because it becoming a snow flurry makes me laugh. Flurry also has extremely little item support - there’s the Fight of the First bow (which would be incompatible with this anyway) and the Quicksilver Coil, and that’s it.
As a bonus, make it also affect one of the Blade Dancer skills. The Marksman skills Heartseeker, Hail of Arrows, and Detonating Arrow (all of which are gated) all have Cold conversions. Falconer has Explosive Trap and (sort of) Net which are both free to grab. Not one of the Blade Dancer skills has a way to do cold conversion. In this case, Shadow Cascade and Dancing Strikes are right out because they require Dual Wielding, so maybe it can affect Synchronized Strike.
The idea of being a sort of hybrid melee build as a Blade Dancer where you hurl frost bombs, zip in and stab things, and then zip out before they unfreeze just seems like something that has a lot of potential and would be pretty fun.