Look, it's been a hot minute since I've ranted about the Dark Crystal, but it's been on my mind recently. But SkekSil is the face of the franchise a lot of the time because not only was he one of the most memorable parts of the original film, but if all the expanded content is to be believed, he is at the heart of the entire story. It's never confirmed that he is 'Dark Heart' the musician UrSkek whose despair tore he and the others apart.
But if it is, then that means he caused everything in the main plot to happen. The Crystal Breaking. The downfall of both Gelfling and Skeksis (because their addiction and obsession with the essence destroyed the skeksis too, make no mistake, and he's the only one of their order to outright kill one of his kind) and if he WAS Dark Heart, then his final words weren't a declaration of malice, or even a rejection of the anti-individualism of his people. It was: is there no being in all of creation who will show me compassion.
SkekSil is a being of heartless want. The others have semblances of loyalty and companionship among them, but not him. And it might have come from his original self's heartbroken belief that compassion and love did not truly exist. Or he craved it so badly he literally tore himself into pieces than comprehend the ache.