It would be Philotes. If anyone was going to be the one and only person to reach out to a lonely grieving goddess, it would be her. Hades felt proud of her. Especially in moments like these, he felt proud to have her. Not that he'd ever tell her that, but he did.
Harmonia's suicidal declaration hadn't alarmed Hades, because looking at her, he had already suspected she was at that point. It just made him sad. Hearing it affirmed like that just made him sad. Harmonia was tired of life. She needed time to rest.
In that moment, Hades knew with a grim reluctant certainty what his answer had to be. She'd been cast out and abandoned by everyone else. Rules or no rules, Hades couldn't abandon her too. If no one else would take her, he would.
“I have an obligation, a duty, to make sure people end up right where they are supposed to be,” Hades began, “Before you presented your case, I had already made up my mind to send you back where you belonged... I still have to do that.” He paused. “But after hearing the details of your situation, it has become clear that where you belong is..here."
"Here," Hades repeated more firmly. "You can stay here. With your husband. Stay as long as you need.” If any of his subjects moaned about Hades bending the rules for her, he dared them to beat her case. When they were married to a dead snake and had their entire families killed in gruesome, terribly misfortune circumstances involving their immortal family, Hades would discuss making exceptions for them too.
“If any problems come up, I'll deal with them.” Hades grimaced a bit as he said that. Someone was going to claim he kidnapped her, Hades just knew it. When a girl and the Underworld were involved, someone always claimed he kidnapped them. You kidnap one girl. One. And suddenly you're branded for life.
“Just make sure that, if you ever decide to talk about this incident with anyone, you present me in the worst light possible.” Say he was a jerk, or a tyrant, or that he'd had greedy terrible designs on her soul from the very beginning. Say reasoning with him was one of the hardest most disagreeable things she'd ever had to do. Hades didn't care. He just didn't want anyone to get the wrong idea. He'd rather have them think he'd kidnapped her than for any of them to get the wrong idea.
Hades reached out to her then. He'd escort Harmonia and her husband to the Elysian Fields himself. Maybe he'd even take her to the poplar tree. He didn't let most people around there, but it was the most serene spot in the area, and Harmonia could use all the serenity she could get.
Someday, maybe she'd want to leave. Maybe she'd regret throwing her life away with her husband's. But for now, Hades thought he'd made the right choice. No one else wanted her. The world broke her to pieces until she didn't work anymore, then tossed her out with no where else to go. Wasn't that the very definition of an Underworlder?