I didn't even think about it! You might be onto smt
It definitely makes sense given the blonde is a close resemblance to the emperor/empress and the eyes are definitely from the Emperor. Her ability could also be a shifter kind as she is clearly a woman but able to swap to the opposite sex and further change her appearance or when as Zenwalker, is the result of overusing her ability.
Although, if that's the case, then who is the brown hair woman clingy to the painting? Didn't resemble the Empress unless the Princess is an illegitimate/concubine's child. However, if being the case scenario, explains why Haron is desperate to getting the painting restore to know the truth behind whatever lies within it.
Anyone else think the princess is the mysterious duke? I know I might be late to this idea lol