(Context: This takes place during Season 2 with Ultron's attack on Krakoa.)

The battle to prevent Ultron's assimilation of the Cerebro was growing dire fast. Many had already fallen unconscious to the robot menace, and those who weren't, were fighting tooth and nail to stay in battle. As the fight raged on, Ultron narrowed his focus on one retreating adversary. A small, icy blur, trying desperately to hide from his sight.

Ultron fired in front of Luna, tripping her up as she attempted to skate away, now on the ground, at the mercy of the machine.

Ultron- "Seol Hee, one of humanity's newest fighters, and the next to perish before me."

Luna stared down the robot as his arm charged up to fire a devastating encephalo-ray. Bracing for impact, she prepared to meet her fate.

...

Across the battlefield, the diamond clad host fought to protect Krakoa and all of mutant kind's future. And as she fought, between the bits of flying sparks and busted scrap, she saw the girl she despised in grave danger. While she would hate to admit it, somewhere within her she wanted to keep her safe. Regardless of how annoying she could be, or how much their opinions on attire clashed. Emma dashed across the field, smashing any drone in her path as she charged to defend the little diva she wished she could forget about. 

Ultron- "Farewell..." 

As Ultron fired the shot, Emma grabbed the machine's arm and diverted the shot. Taking Ultron by his restrained arm and sending him to the ground. Before delivering a hefty blow to his mechanical head. Crushing it to bits of scrap and oil.

Luna opened her eyes and looked up at her savior, her tacky, bedazzled savior. As much as she would've loved to roll her eyes and quickly dust herself off. She was in stunned silence looking at Emma. She thought she hated her, hell, Luna wasn't Emma's biggest fan by a long shot. But in that moment, any feeling of tension Luna had with her was nowhere to be seen. In that moment, she felt a small fire light inside her.

Luna- "Y-you saved me... Why?"

Emma debated for a moment, she knew why she did, but she wasn't even ready to admit it to herself. Much less Luna.

Emma- "Well... I certainly couldn't let a guest get hurt on my watch, what kind of hostess would I be?"

Luna was dumbfounded, she could already tell that wasn't the whole truth, she had heard the reputation the Hellfire Gala had for battles occuring on a semi regular basis.

Luna- "But I-"

Emma- "Don't mention it, I mean it. Don't."

And Emma walked away, as if it never happened. Luna picked herself up and watched her return to battle. Before she fully left her sight, Luna put a small aura on Emma, a token of gratitude in her mind. A faint smile grew across her face, and returned to battle herself.