Echo's idea worked perfectly. When she and the disguised Changelings flew to the castle gates, the guards immediately let them in.
"Like I said, they didn't bat an eye," Echo reassured them as they landed inside. "You two can change back now."
Thorax and Pharynx nodded and changed back to their normal forms. The three went to the throne room, Echo leading the way. When they reached the throne room, they saw the Princesses, the Mane Six, Spike, Starlight, an orange unicorn, and six unfamiliar ponies.
They grey bearded unicorn's eyes widened upon seeing the Bat Princess as they locked eyes.
"Twilit?" the blue-robed stranger asked. "Is that you?" His eyes narrowed at seeing her marred coat as he muttered, "No, it's been a thousand years since we left. And Twilit never allowed anyone to scar her coat."
"Echo, how lovely that you came," Luna greeted the Bat pony. "Starswirl, this is Twilit's descendant, Princess Echoing Shadow. Though she prefers to be called Echo."
"And who might your friends be?" Echo asked.
"These are my own companions," Starswirl gestured. "Stygian, Mistmane, Mage Meadowbrook, Rockhoof, Flash Magnus, and Somnambula. I am Starswirl the Bearded; we are the Pillars of Old Equestria. According to these young mares, we were the original Elements of Harmony, besides Stygian. We've been sealed away in a timeless dimensional gap, Limbo, for a thousand years."
"We didn't understand Stygian wanted to join us in battle back then," Mistmane explained. "So we instead cast him out, causing him to turn to darkness. But now we understand the truth."
"If you'd understood sooner, a lot of things wouldn't have happened," Stygian murmured. "Namely, me becoming the Pony of Shadows."
"Well, Stygian," Echo turned to the colt, "if there's one thing that Starlight, Trixie, Discord, and the Changelings know, it's redemption. At least now Thorax, Pharynx, and I know the source of those clouds. But everypony, I have done some research on the Bat ponies' crown jewels, and you'll be surprised. The jewels are actually created from the Tree of Harmony."
"What?!" Twilight and the orange unicorn shrieked.
"How?!" the Princess of Friendship demanded. "Last I checked that shouldn't be possible!"
"There simply shouldn't be a seventh Element!" the orange unicorn shouted.
"Sunburst, Twilight, calm down," Starlight spoke up. "Echo, there are only six Elements of Harmony. A seventh Element just isn't possible."
"But it is," Echo stated firmly. "There was supposed to be a seventh Element to portray their true might, grown in a sort of fruit on the Tree of Harmony. But it was taken away by the usurper who wished to rule the Bat ponies. When my ancestor, Queen Twilit, took back the jewels, she awakened their power and did away with the usurper. The jewels themselves already had the protection spell on them."
"So what concept does it represent?" Rainbow asked.
Echo hummed. "My guess would be the Element of Freedom. After all, think about it. Honesty, Kindness, Laughter, Generosity, Loyalty, and even Magic; you can't have any of that without the Freedom to do so. I and a huge group of orphans know; we've survived the Nightmare Orphanage and its demon-owners-masquerading-as-Pegasi. You'll know everypony who's been there from our scars."
"Oh, what a horrifying thought," Somnambula gasped. "In all these centuries, we never dreamed that there would be such a place in our absence."
"And I don't think any amount of healing would be able to mend those kinds of wounds," Meadowbrook cringed, seeing Echo's nasty assortment of scars.
"I've never seen anypony like you two before," Rockhoof mused, looking at the Changelings.
"Well I'm Thorax, king of the Changelings," the taller of the two grinned. "This is my younger brother, Pharynx."
"Uh, nice to meet you," the shorter Changeling nodded politely at the tall Earth pony.
"We had a bit of a run-in with each other on the flight here," Echo explained, walking between the enormous stallion and the teal-skinned Changeling, brushing their wings against each other in the process. Pharynx shivered at the sensation as another blush spread across his face. "But neither of us were watching for anypony else, so it's kinda more of a crash-in. It's not like it was intended or anything." She turned to the brothers. "Besides, I've met Dragonfly, Damselfly, and Crane Fly; they're pretty sweet little Changelings."
"And they're also the fastest fliers in their entire brood," Thorax added proudly before turning to the Pillars. "If you guys ever want to pay the Changeling Hive a visit, our doors are always open."
"And I'm guessing the Bat Palace will be the same way?" Pharynx asked Echo.
The Bat alicorn nodded. "Of course. You can come by anytime. But for now, I'm sure you all want to see where you all once lived before you were trapped in Limbo for a millennium."
"That we do," Magnus agreed. "And we'd be glad to pay a visit every once in awhile."
"Equestria has gone on without all of us," Starswirl added. "And we wish to see how much has changed."