Tell me what you think about an Idea I have been coming up with

So I have been thinking about how to make an assassin with interesting mechanics that would make every single fight interesting and require both skill and knowledge. The main Thing I have come up with is the passive: The character wields a short sword in one hand (possibly reverse gripping a wakizashi or other short katana style blade) and a dagger in the other. Every ability and auto attack switches between the dagger and sword. The dagger would deal additional damage from behind while the sword has a stronger, but slower attack. Both the dagger and sword have different basic abilities with the sword focusing more around straight forward and aggressive attacks while the dagger has more stealth and ninja styled abilities. Im not sure what the ultimate would be but it would be the same for both weapons and would possibly unlock the use of a special ability which combines the dagger and sword ability on a moderate cooldown. Tell me what you think about this idea.