This is being cross-posted from Ao3. It was originally posted on 16 February 2020.

Huge thank you to GaeilgeRua for allowing me to use her Grammarly to beta this. Any other mistakes are definitely my own.

Disclaimer: Harry Potter belongs to JK Rowling, Bloomsbury, and Warner Bros. Marvel belongs to Disney. No copyright infringement is intended.

Prompt: 2019 Roll-a-Thon- Crack Fic: Healing/Superpower/Magic Swap
#MMFBingo19: N1 Wartime Romance
#ExcelsiorBingo19 Square: G4 Mild Dub Con

The rain poured down in buckets as Steve made his way through the thick forest. He had no idea where exactly he was going, only that he needed to find shelter before he was either struck by lightning or eaten by a wolf. It was well after midnight, and wherever he ended up did not appear to be the safest of places on a cold November night.

In fact, Steve wasn't even sure what Tony's new device actually did. The overly talkative man had all but insisted that it was a necklace with time-travelling powers, but that didn't help the situation. If Steve had travelled in time, he knew not where he was or what was about to happen. Upon his arrival, a massive thunderstorm greeted him.

Suddenly, Steve paused in tracks, having heard a rustle in the trees to his left. "Show yourself," he shouted over the raging storm, unsure whether or not the person could even hear him. Squinting, he could make out the outline of a male figure lurking behind the trees. A second later, as lightning illuminated the forest, a rather thin man stepped forward.

He had dark eyes and long black hair that was slicked down from the pouring rain. Steve hed his shield firmly in his hand, ready to combat whoever this strange man was. Who would be in the forest in the middle of a massive thunderstorm? Perhaps he was a villain, and Tony's unusual necklace had brought Steve to destroy him.

"I'm Regulus," the man said confidently over the thunder as he took another step toward Steve. "I was told of your arrival and came to find you. We are destined to meet here this night."

Steve almost stumbled backwards at the strange statement, but many years fighting alongside Tony and the rest of the Avengers kept him from fleeing. "Where are we?"

"This is the Dark Forest," Regulus explained. "You are just outside of Hogwarts School of Witchcraft and Wizardry."

"Does that make you a-"

"A wizard, yes," Regulus finished and then stopped right in front of Steve. "You don't know it yet, but you and I are going to become quite close."

Confused, Steve opened his mouth to further question the man only to find that he was no quite speechless. Regulus had roughly grabbed Steve behind the neck and all but slammed his lips atop his own. The kiss was relentless and bruising, and, for a second, Steve had the right mind to shove him away. Only something stopped him.

This felt oddly right, albeit a bit strange. Suddenly, a bolt of lightning struck the small clearing in which they stood and threw the pair backwards. The last conscious thought Steve had was that he was going to absolutely murder Tony when he finally made his way back to the present time.

. . . .

When he awoke, Steve was aware that something was entirely wrong. His body felt drained and weak. In fact, this was precisely how he felt pre-Super-Serum in 1941. That wasn't all, though. Something was tingling just below the surface. Something new. Something unfamiliar yet exciting at the same time.

Opening his eyes, Steve saw Regulus standing by the window. Shakily, he sat up and cleared his throat. Regulus turned around and gave him a serious sort of smile. "I take it I have been asleep for a while."

"You've slept for about a week or so," Regulus explained softly as he made his way toward the bed. He sat down on the edge. "I had to use magic to heal you. I hope you don't mind?"

"No," Steve said softly, astounded that this unknown wizard was helping him at all. But then again, there was that kiss…

"I suppose you would like an explanation of what happened?" Regulus prompted, a wry grin on his lips.

"It would be a good place to start," Steve suggested with a grin and a quirk of his eyebrow. "I feel like I've been hit by a train."

"More like a magical bolt of lightning," Regulus said and then ran a hand through his dark, curly hair. "It transferred your super-strength powers to me, and my magical abilities to you."

"I have magic," Steve gushed and then glanced at his hands. That must be the strange feeling that was coursing through him right now. "That is… Unexpected, to say the least."

"I do apologize if I was a bit forward that night in the forest," Regulus continued to say. "We are in the middle of a war here, and I needed your help. I wasn't sure you would willingly offer your powers to me in exchange for magic."

"Is this permanent? I will need to return to the future eventually," Steve said, now slightly worried he would be stuck here forever. He should feel angry for having his powers stolen, but he had been given magic in exchange.

"No," Regulus said quickly, reaching for Steve's hand. "I promise to give your powers back once I have defeated the Dark Lord… Or, at least, done my part to thwart his takeover in the future."

Steve didn't mind that Regulus hadn't let go of his hand. It felt warm and comforting, and a sudden idea struck him out of nowhere. "I may be far weaker in this state, but teach me to use magic, and I can help you defeat this villain of yours."

Regulus glanced at their joined hands and then smiled. "Absolutely," answered and then quickly added, "And I do promise to return your powers to you once we get the task completed. I never meant you any harm."

"Then we better get started," Steve said resolutely. "It has been quite a while since I've felt so helpless, but I feel this is for a good cause."

"I wouldn't have done this to you if it wasn't, but I had no other choice," Regulus told him resolutely.

"I forgive you, Regulus. I'm curious about this Dark Lord and protecting you." Without another word, Steve leaned forward and allowed the wizard to close the gap between them.

Whatever this was that was brewing began with Tony's strange device and lead him to this point in time. Steve wanted to find out more and why he felt so compelled to be with Regulus. Whatever happened during this war, Steve was ready and willing to see it through to the end.