And so it was written that when Princess Platinum found a very special somepony and a proper wedding was arranged, she would not be satisfied marrying a normal unicorn that would be only her consort. She commissioned a grand crown be forged with dazzling gems of deep arcane worth to accompany.
The gems would act as an all-purpose magical tool, building on and enhancing the unicorn's magic, enhancing them. There was a dark side.
Sunburst huffed. "Why do they always have a dark side?"
Starlight shrugged. "This one's pretty mild as dark sides go." She pointed to the passage that explained it. Princess Platinum had no interest in creating a king that would depose her, so the crown would only work with the input of a royal mare. Her presence and will was needed to keep it going. Lose her faith and it would stop working and the unfortunate stallion would be left where they started, at the least.
The book didn't go heavy into details about that, since it didn't happen.
Twilight lifted her forehooves in an expansive shrug. "Well, that isn't so bad. You have a royal mare right here." She directed one of her hooves at herself. "And she has no particular issues with you wearing this crown. I can't even imagine you doing something bad with it."
Starlight waggled her brows. "He may use its awful magic to study as no pony has ever studied before!"
Sunburst softly coughed into a hoof. "I will keep my wild urges at bay, promise. Uh, well, if Princess Platinum made it for her boyfriend, I doubt it was very dangerous, or that would be remembered. Getting married, plonking this on a pony's head, and they explode; people would talk about that."
Twilight stuck out her tongue at the mental image thus conjured. "You would think so... Well, then shall we?" She lifted the crown in her magic, angling it towards Sunburst. "I mean, you are a boyfriend of a princess. We're almost repeating history here, though the book didn't mention any lessons we should be learning from the fact."
Sunburst gently took the crown in his own magic. "Well, sure. I mean, we all want to know how it works. If it's not a cursed artifact, why not?" He raised his hooves as the crown floated over. He lowered his hooves and the crown lowered with it, resting on his head. Everything went dark for him. He stopped moving, staring ahead.
In his mind, he saw a mare approaching him in a slow and sultry walk. "My hus..." Her voice trailed off as she looked over him. "You are not him." Her blue eyes narrowed a little. "I may be but an echo of the lovely Princess Platinum, but even I can see that. Did you steal the crown?"
She did not wait for him to reply, her horn glowing brightly as she pulled something precious from within Sunburst's stunned head. "No, not a thief... She's dead..." The phantom sank to her haunches. "For countless moons..."
"I'm sorry?" Sunburst rose shakily to his imagined hooves. "Uh... where are we?" Around them were countless lines and swirls. Dizzying fractals that branched out in three dimensions bedazzled the eyes, seeming to change depending on the angle they were viewed from. "Is this inside the crown?"
"This is my home." She sat and spread her hooves. "I, a small shred of Princess Platinum, the only tiny piece left, if your mind speaks truly." She heaved a sigh that had no air. "You cannot imagine how this feels..."
"I can imagine," he said, defying the words she had literally just said. "It must be awful... Do you want me to go?"
"No!" She took a step forward. "No... I've been alone for so long and you're so fast to throw me back into that darkness? No. Tell me, what Princess gave you the crown? Show me her."
He thought of Twilight, barely a flash, but it was enough for a double to appear before Princess Platinum. "Hmm... An alicorn?" She circled around Twilight, appraising her. "How good is she at magic?"
"Very," quickly replied Sunburst. "My name is Sunburst, by the way. She's Twilight, my girlfriend." He blushed at the admission.
"Girlfriend?" She hiked a refined brow, tossing her pink mane. "You are not even wed, not even betrothed, and she would trust this crown on your brow? You have her trust, or she has no idea what she has done."
"I would like to think I have her trust." He canted his head a bit to the left. "I wouldn't ever do anything to hurt her. She was my friend before my girlfriend."
Princess Platinum stepped closer to Sunburst, raising a hoof to brush along one of his cheeks. "Mmm, loyal, good. A stallion should be just that to a fair princess, though she is not as fair as I am." Being a white pony with pink mane, she was quite brighter than the purple Twilight. "Tell me, and be truthful, you already know I can see straight through you. Will you use this crown for her benefit?"
Outside the dream realm, Twilight and Starlight blinked at the suddenly unresponsive Sunburst. Starlight pulled the book over to peer at it. "They don't mention this part."
"Is that all you can say?!" She hopped to her hooves and quickly circled the table to Sunburst. "Sunburst? Are you alright? Should we take off the crown?"
"I'd vote against that." Starlight rolled a hoof towards the crown. "Something's going on I bet, and yanking that off may make things get ugly.
Twilight tilted her head a little as she leaned in close. "I think it's glowing..." The largest jewel was dimly shimmering. "Something is happening..." She crashed to her haunches. "Something good?"
"We can only hope." Starlight lifted her shoulders. "Too late for regrets now."
"That's easy for you to say." She waved a wing at Starlight in a few frantic flaps. "Your boyfriend isn't the one with his brain maybe being melted by an ancient artifact?!" She clopped both hooves to her own head. "Why did I think this was a good idea?!"
Spike peeked his head in, sighed, and withdrew. It was time for panic tea #2.
Sunburst took a half-step back, but it didn't seem to actually bring him any further from the ruler of that strange domain. "I... Yes, of course." He wasn't sure he'd only use it for her benefit, but saying anything but yes felt foolish to him.
"You're lying." She poked him right in the center of his chest. "But only a little... A little lie is sometimes called for in royal circles." She smiled thinly. "Let us revisit that question from a new angle. Do you swear to never use the crown in any way that would impede or harm her?" She gestured at the floating transluscent statue of Twilight. "She isn't me, but she is a princess, and I won't have another princess being betrayed at my hoof."
"Never intentionally," he quickly blurted. "I mean... I don't even know how this works. We're study buddies, not rivals."
Platinum blinked at that. "Study..." She reached out and brushed his glasses. "Is she as studious as you appear to be?"
"Oh, um... yes?"
Platinum smiled gently. "How adorable... a demure book-loving princess, and a partner that would eagerly hide in the same pile of books... Adorable..." She leaned in closer, fluttering her long lashes. "Very well then. Your ardor appears to be true. Your faith, sincere. You love her, and more than simple propriety demands. How... fortunate for her."
Sunburst took a step forwards. "Wait, did you not... love your husband?"
She smiled, a haunted smile. "I thought I did, once... I learned he did not return the feeling. He agreed because I was a princess, and feared saying otherwise. He agreed because he thought he had to. He whispered sweet words, because he thought he had to. He held me in his hooves... because he thought he had to..." She sank a little. "My true self never learned this, but how could I not? His mind was open before me. I saw the truth, the naked truth of it. He had no love for her, only fear and obligation. I kept him in line, but I could not force him to care for me..." She reached for his nose, booping him gently.
"Your princess is very fortunate indeed..."
Sunburst suddenly started awake, eyes blinking rapidly. "What?" He was just as quickly tackled to the ground with a frantic Twilight hugging him tightly. "Woah-hey, um... I'm alright, promise..."
Starlight waved a hoof at their prone forms. "See, that wasn't so bad. You may want to avoid choking him to death though. That would defeat the whole thing."
"Oh, um, yes." Twilight scrambled back up to her haunches. "What happened? Are you really okay?"
Sunburst sat up with an unsure smile. "I met Princess Platinum."
Twilight's eyes widened. "What?! Details, now."
He pointed up at the crown firmly on his head. "Huh, you would have thought being knocked over would have..." He reached up and tried to remove the crown, but the crown was quite firmly attached. "Oh, uhhh...."
Starlight's horn glowed as she grabbed the crown and gave a firm yank, drawing a yelp from Sunburst. "Nope, pretty stuck on there. At least it looks good on you."
"Um, thanks." He rubbed at his head, trying to calm the flesh she had just tugged on. "She's in here, a small piece of her. She wanted to be sure I'd be loyal to my princess."
Twilight tilted her head. "Well, seeing as you're awake now, I assume you passed her test?"
"I think so..." He rubbed at his cheek. "She seemed so sad though... I mean, she's, you know, happy for you, Twilight, but she only just learned that the real her is long passed, and her husband never really loved her."
Twilight flicked her ears back, cringing. "Oof, that's a harsh way to wake up... Is she alright?" She peered at the largest of the jewels. "I have nothing but respect for Princess Platinum," she spoke to it, unsure she was being heard. "I will handle this crown with the utmost of care."
Sunburst smiled a little. "It feels warm. I think she heard you and she's, I'm not sure, happy? Content?" He stood up, his eyes upwards on the bits of the crown he could see from that angle. "Well, it's official now."
Starlight hiked a brow. "What's official?"
Sunburst pointed at Twilight. "I belong to her."
Twilight darkened rapidly, blood flooding her cheeks. "Sunburst! You are an adult pony with certain rights. No creature can own you!"
Sunburst softly tapped at the secured crown as he paced around the room. "She, uh, the bit of Princess Platinum, will make sure of it."
"No!" Twilight clopped down a hoof. "I don't want that."
Starlight rolled her eyes. "He's already fallen for you, may I remind? I doubt much will change." She leaned forward a little, her chin on her hooves. "Besides, what's a little mental magic between good friends?"
"Starlight!" Twilight's wings shot out in either direction. "Sunburst... Please don't talk like that. You're not mine. You are an independent pony. If you decide you don't want to be around me, then I formally give permission for you to do that." She nodded firmly, eyes on the largest jewel of the crown. "You hear that? Don't force him to do anything. I trust him, all of him."
Sunburst perked an ear at a voice only he could hear. "She really loves you," the voice whispered as if from inside his skull. "I said much the same thing to my special pony... He said yes, but his heart said no. Do you trust her just as deeply?"
Sunburst smiled faintly. "Whatever happens, uh... I'm happy, here, with you." He leaned in and touched noses with the blushing Twilight.