1st
Twilight and Tranquil landed at the entrance to a cave near the Bat Empire.
"This the place?" Twilight asked, looking over to Tranquil.
"Beats me, I wasn't present when Tia gave you the locations." Tranquil said.
A batpony stallion with pale blue coat, short bright orange mane and tail, slitted blue eyes, and a cutie mark of three yellow bats making out the shape of a triangle stepped out. "Good morning princesses, I'm Blade Wing. I trust you are here for a disguise correct." the batpony, revealed to be Blade Wing, said.
"Yes, I'm princess Twilight Sparkle, and this is Princess Tranquil Wind." Twilight said, Tranquil didn't complain about being called princess.
"It's a pleasure to aid you, follow me into my lab."
The Three headed into the cave and soon made it to Blade Wing's lab. Blade Wing's lab had countless high quality machines with some magic based devices and some technologically based devices. On the table that Blade Wing had moved over to was what appeared to be a silver bracelet that seamed to glow with faint magic.
"This device will bend the light rays around you to give the illusion that you're just another batpony. Only Princess Red Fang and I know of its existence." Blade Wings said.
Twilight nodded and went over to where Blade Wing was. "Tranquil, how are you going to hide yourself, seeing as there's only one device?" Twilight asked.
"Simple, I'm just going to use changeling magic, after all, I was a changeling during one of my shifts." Tranquil said as her horn lit up in a green aura that seemed almost entirely stable. In a flash of green flames, Tranquil looked exactly like a normal batpony version of herself, complete with bat-wings, fangs, slitted eyes, bat-like ears, and no horn. "Before you say anything, I'm not breaking the law by toying with forbidden magic, the law relates only to ponies, I'm technically not a pony."
Blade Wing finished getting the device on Twilight's hoof then and her form seemed to fade from alicorn to normal batpony. "This device only bends the light so it's not fool-proof. Try not to come into physically contact with any batponies as if they feel your wings or horn then they'll know it's an illusion." Blade Wing said before going over and checking Tranquil, showing shock at finding that tranquil was a perfect physical match to a batpony. "How?"
"Changeling magic warps the body, making it a perfect copy of what the user is wanting, only the most practiced users are able to formulate a perfect disguise without much of a reference."

After a bit of talking, during which Tranquil and Twilight learned that Red Fang was a lot like Rarity and preferred to be treated as the princess she was, the two flew off to the castle.
"What did you mean when you said shifts?" Twilight asked as they flew towards the castle.
"That's what I usually call each time I have a new set of Elements of Harmony to guard." Tranquil answered calmly.
Twilight fell silent after that as her thoughts began to drift. After only an hour or so of flight, the two landed at the front of the castle and Red Fang opened the gates. "Good morning Princess Twilight Sparkle and Princess Tranquil Wind, I've been expecting you, please come in." Red Fang said.. Red Fang had a black coat, slitted silver eyes, and dark purple mane and tail with the mane going down to right above her front left hoof.

2nd
The Vampony Pegasus mare ran through the streets of Vamponyville as she tried to shake her seven pursuers with the ancient sword she had taken still in her mouth. She looked behind her, only to see two alicorn vamponies, two Pegasus vamponies, two earth vamponies, and one unicorn vampony right behind her. Damn, they're still following me, I should know better than to try and outrun the Elements of Chaos the vampony thought as she took a corner as fast as she could, hearing the sound of the ponies crashing into the wall. She looked behind her again and found that four of them were still pursuing her. Great idea Solar Sun, steal the all powerful ancient sword from the heavenly guarded ancient castle within the ancient evil forest while the Princess of the Night is wide awake and the ancient magical beings of Harmony-turned-Chaos are walking around during a sleep over with only one dagger and zero magic, as well as weak wings. Yea I just don't know how this could have possibly gone wrong. Oh and top all of that off with the fact that I don't have the slightest clues as to just how this thing works nor why my employer would want it in the first place She took another turn as fast as she could and spotted the portal that would lead her back to her employer. She jumped through and the portal closed behind her.
The Elements of Chaos and their knew ally, the guardian of the Elements of Chaos, Shifting Wave, skidded to a halt as the portal closed.
"We missed her." Midnight Defiance hissed.
"We should have sent somepony to check for portals before we even began to pursue her. Who was that anyway?" Night Blood asked.
"I don't know, though it's nice that I showed up in time to have some fun." Shifting Wave said.

unknown location
Solar Sun walked into the throne room carefully, keeping her head hidden by the white cloak she wore Why did I go with white when it's always dark in the world? she asked herself.
"Have you succeeded in the task give to you?" a dark male voice asked.
"You wanted that cursed blade I've delivered." Solar Sun said as she set the sword down at the base of the throne and held out her hoof, revealing it to be dark bluish grey. "I've done my part, now you do yours."
"Of course." The large stallion handed Solar Sun a large bag of bits.
"I trust you aren't trying to trick me, because I will ensure I get my full pay and your blood if you are."
"I wouldn't do such a thing."
Solar Sun left the room after that, but she put her ear against the door the second it had closed, seeing as there were no guards.
"Finally, with this I'll destroy this dimension and the next, and nopony, not even those pathetic Elements of Chaos, can stop me." came the muffled voice of the stallion, Solar Sun left after that.
I can't let him do that, oh how I wish I hadn't excepted the job. I need to warn the Princess, I just hope she listens After that thought crossed her mind, Solar Sun broke into supernatural speed and headed back to the Castle of the Royal Pony Sisters. While running, her hood flew back, revealing her glowing red eyes and her blue mane styled similarly to Night Blood's mane, though slightly different.

1st
"Thank you for speaking with me." Red Fang said as Twilight and Tranquil left.
"Great, now I need to go to the Everfree Hive, this better not be some trap." Twilight said, almost hissing.
"If this Princess Shadow Mind is anything like Chrysy was then I doubt it's a trap, she's likely just wanting to make getting food for the hive easier since friendship is a powerful force, strong enough to feed an entire hive with ease, and obviously The Friendship Rainbow Kingdom would be full of it, having the Princess of Friendship herself living there." Tranquil said.
"I still don't think I should trust her."
"Think about it this way, if the peace negotiations go over nicely for you and her then, while I'm catching up with Chrysy, you can learn more about changelings and changeling hives." Tranquil smiled after that while Twilight's eyes lit up.
"Then what are we waiting for?" she asked before going almost triple her original speed, if Tranquil wasn't a great flier then she would have been left behind, luckly she was able to easily keep pace with Twilight.
Knew it'd work she thought.

Author's Note

This will give you a taste of how chapters that occur in both dimensions are.
The stallion will be an OC I create later, but who is Solar Sun's counterpart in Twilight's dimension?