Hades nodded “Hel.” His equal. The only other person who could compete was his wife, and Persephone wasn't just his equal, she was his opposite. There were things that Persephone would never understand, because she was the goddess of spring and both worlds were always open to her. Hel, by her very nature, understood all those things. Hades had never met anyone who shared not only status, but patronage too. It was nice to meet her. Maybe he wasn't alone in the universe after all.
Hades unlocked the gate and led her up the path towards his palace. He had a strange urge to show her everything. Every in and out. Even the truly unpleasant places like Tartarus. She was the first person he met who Hades felt might actually appreciate it. She was the first non native who might look past the dank and dreariness, and see what Hades saw.
Of course, he couldn't actually show her everything. His realm was large enough to hold all of his dead, and his future dead comfortably. No one had that much spare time. Still, as they were moving, he tried to point out what he could. He gave a short rundown of each of the rivers in the distance, and their uses and properties. Past the vaults that littered the ground like gravestones, one could get a glimpse of the fields on one side, and Elysium in the distance on the other. The court would be too hectic, but he did point it out as they passed it. The last things he showed her were the orchards, and Persephone's gardens, which he described in probably too much detail. They were the most beautiful places in his realm, besides the Isles, or Elysian Fields. But those had to be beautiful, so they didn't count.
When he was finished showing her around a bit, Hades paused in case she had any more questions or comments, before leading her to his study. He was very wary about taking up too much of her time. She may have said she didn't have anything, but Hades knew exactly how busy ruling an Underworld could be. The light in his palace allowed him to notice her in greater detail, but this did nothing to change his initial opinion, though it did cause him to wonder a few things.
Had she been cursed? Was there an accident? Had she just been born this way? Was she from a family of equally deathlike beings or was she unique? Special. Ruler over her dead because she had that connection that no one else did? He wondered how she became queen. Was it by merit, or birth? Who was her family? Had she grown up in her realm? Hades had never listened to or sought stories about other pantheons, because he didn't see the point, but now he wished he had paid a bit better attention. Maybe he would have thought to call upon her sooner.
“Have you always been like this?” Hades finally asked. His tone conveyed only mild curiosity. He didn't really care what the answer was to that or any of his other questions, one way or the other any answer was acceptable, but he wanted to know more about her, and hoped she wouldn't mind him asking. She hadn't seemed sensitive when she'd caught him staring, but it was hard to tell with goddesses. Hera didn't seem sensitive either, until you opened your mouth.