I’ve decided that the thing that hurts most about s1 Jang Uk vs. s2 Jang Uk is that the sharp, inquisitive, openly spiteful part of him is now so muffled by grief and hopelessness. It’s still there, but he’s been cut down in a very real way, as we saw in the flashback with Park Jin. He was forced to give up on avenging his love, forced to work for the people who were to blame, forced to tame his ambitions and his image to make others more comfortable. He’s bearing this immense power that’s more a millstone than anything, and he’s bearing the knowledge that his lover is dead, and in the cruelest way possible. Not to mention the trauma of dying violently, resurrecting as an all-powerful monster, learning that he was born from rape and sorcery… He’s in a dark place.
And now he has Bu Yeon, who is the open, unbroken, unknowing soul of the woman who trained him, loved him, and murdered him, the woman who gave him purpose and agency for the first time in his life and truly Saw Him. And now she’s doing it all again, and of course he’s falling in love with her again. And that light is coming back into his eyes, the mischief and the cunning and the determination. He came back to life 3 years ago, but now he’s finally living again. Because of her.