The Crystal Empire had caught its breath after the tumultuous fair. The air, thick with ringing laughter and music just yesterday, was clean and fresh on the morning of a new day. In Sombra's room, bathed in the dawn sun, only dust motes stirred from the sheets by his sudden movement danced.
He lay in bed, feeling strange. Strange after the terrible heaviness and pain that had gripped him so recently. It happened every year, on the same day. His body would become leaden, his mind clouded, and the world distant and hostile. And every time, as if on schedule, she was there. Radiant Hope.
The only one who had been with him all these years, even on the day of the Crystal Fair, when the whole city rejoiced, she had refused all festivities and never left his bedside. And every time, Sombra felt ashamed.
The door creaked.
"Sombra? How are you?" He forced himself to smile.
"It's all gone," he breathed out. "Just like a wave of lightning."
He looked at her, at her clear eyes, and a lump rose in his throat.
"Hope... I... I'm so sorry. Because of me, you missed the Crystal Fair. Again. You should have been having fun, and instead you were stuck here..."
"Don't apologize," she interrupted him softly, coming closer. "It's not your fault."
"But you deserve a holiday!" he insisted.
"You don't have to be my babysitter. Next year, you should go; I can handle it."
Hope shook her head, and a warm, understanding smile spread across her face.
"You don't understand, Sombra. Sitting here with you, I don't miss out on the holiday. You give me something so much more."
He looked at her, confused. What could he, always sullen and withdrawn, give her?
"Your trust, you show me the part of you you hide from everyone. And that's worth more than all the fairs in the world."
She came over and leaned toward his face.
"And so you no longer doubt it, I want to do something for you."
Sombra became wary. Hope walked to the edge of the bed and pulled the curtains shut, then, taking the edge of the blanket pulled over his legs, carefully pulled it down.
Sombra flinched involuntarily.
"Hope? What are you planning?" his voice was tinged with alarm.
"Quiet," she placed her graceful hand soothingly on the back of his foot. "Trust me."
She made herself more comfortable, kneeling next to the bed, and with her magic, she placed several pillows behind Sombra's back. She took his wide foot in her gentle hands. Sombra froze, every muscle in his body tense.
She began the massage. At first, it was light, kneading movements all over his foot. Then she pressed her thumbs into his heel and began working every inch with incredible precision. The tension that had been building up within him for years began to slowly, reluctantly recede. He relaxed, though not immediately, his shoulders slumped, and his back gently pressed against the pillows.
He closed his eyes, immersed in bliss. And then she changed her movements.
Sombra felt not the warmth of her palms, but something else—a light, barely perceptible, moist touch. He opened his eyes slightly and saw something incredible: Hope leaned over his foot and gently, almost reverently, touched his heel with her lips.
Her lips and tongue moved upward, reaching his toes and then back down, brushing against sensitive spots along the way. Sombra snorted. Then again. He tried to hold on, but then he laughed. Easily, truly, throwing his head back and squeezing his eyelids shut, treacherous tears welling up beneath them. Hope smiled, looking at him, and continued her gentle ritual, kiss after kiss washing away his fatigue and listening to his surprisingly ringing laughter.

I recently met the wonderful artist  Forfun2, and it was through conversations with him that this idea was born)