So I've been hearing a lot of theories lately, and some of them turned out to be true in Steven Universe, like being more than a single Diamond ruling Homeworld, before the war, and more that might be true. So, as a far prequel to Echo in our Minds, here's MY theory of after the war, and what Yellow Diamond was, before she was truly ruler of Homeworld, when she first met the new Diamond Authority.

Steven Universe: The Cold Heart of Homeworld

Chapter One: The Arrival

Things on Homeworld were quite different, before the war for Earth. Back then, it was peaceful and the Gems lived in harmony. But on Earth, the rulers of Homeworld had Kindergartens stationed on Earth, which were draining the Earth's life energy, to create more Gems. This continued, until Rose Quartz shattered Pink Diamond and led a rebellion to defend the Earth, and were successful, but many casualties were resulted in the great war. Years later, Yellow Diamond seemed to have vanished from Homeworld, after the failure, and from there, the remaining Diamonds, Red, Black and Orange, ruled Homeworld, while White, Blue, Purple and Green Diamonds went into hiding, and though the last three Authority members were successful in restoring Homeworld, some Gems were still reluctant to obey the reformed Authority, and thus, restoration progression was slow, without Yellow Diamonds leadership.

Years later, after the war…

Peridot and Jasper were in the elevator, heading up to the reception area, to meet with the Diamond Authority, as the elevator stopped, the doors slid open, revealing a Japanese-styled garden, and the three remaining Diamond Authority members, Black Diamond standing on the bridge, Red Diamond stood next to the cherry blossom tree, and Orange Diamond stood next to the lake, all three wearing dark cloaks

"Peridot and Jasper." Black Diamond declared, welcoming the two "Welcome."

Peridot and Jasper bowed, before entering the Japanese atmosphere.

"Hmm, cherry blossoms…" Peridot hummed.

"Yeah." Jasper bluntly said, showing distaste.

"I take it you're not a fan, Jasper?" Orange Diamond asked with a crooked smiled.

"No." Jasper growled, before wiping a fallen cherry blossom off her shoulder "They make me sick." Orange Diamond chuckled at her response, as Jasper crouched down near the lake, looking at her reflection "I knew that Serpentine and her team was working on some fancypants new reception area… but by the stone, when I get my hands on her…" She stood up and turned to Peridot "She'll be lucky if she can carry her box of crap out of the building."

"Is it really so horrible?" Peridot chuckled, gesturing to the cherry blossom tree "They're only trees."

"They go from full blossom to bare in a week. One mucking week!" Jasper growled "I swear, I hear the troops, all the time, saying "Oh, it's so fleeting and beautiful…" Pathetic." She turned to Red Diamond "My Diamond, you've been to Earth more times than anyone, asides that Rose Quartz traitor! What do you think?"

"Nature is just nature." Red Diamond chuckled, as a cherry blossom landed in her hand "Not beautiful, not ugly." She let the blossom slip from her hand, as it fell onto the lakes surface "The wind blows, the flowers float away. It's simply how things are."

Jasper stifled a grunt, as they crossed over the bridge.

"In any case," Black Diamond spoke up "Minuano should be here shortly."

"Minuano," Jasper declared, with a smirk "The cold heart of Homeworld."

"A.k.a.," Peridot nodded, with a smile "Yellow Diamond."

Meanwhile, on Earth, at the Kindergarten…

At the Kindergarten, a Yellow Pearl, carrying a satchel, parked her motorcycle, and stepped onto the warp pad, and warped to the Galaxy warp. After making sure she wasn't being watched, she brought out two flask robonoids. The two robonoids used their repairation liquid to repair the Homeworld warp pad. Smiling, the Yellow Pearl laid out an Excalibur sword, and a yellow diamond gemstone onto the ground, as the gemstone started to spark, before forming a silhouette, and Yellow Diamond emerged, while remaining the normal size of an adult human. The Yellow Pearl held up the sheathed sword, and Yellow Diamond took the blade and strapped the sheath to her waist.

"Make sure no one follows." Yellow Diamond said sternly "I will return to retrieve you, once I deal with the imposters."

"Yes, my Diamond." The Yellow Pearl bowed, smiling "And do be careful, my Diamond."

"I'm always careful." Yellow Diamond snorted with confidence, before stepping onto the warp pad, and warping away.

I hope you guys enjoy this new story. See, my theory is that after the war, Yellow Diamond leaves Homeworld, travels the galaxy and becomes stronger. After finishing her training, she gets word that a new Diamond has reformed, so she returns to Homeworld to deal with the imposters. So, that's my theory. If you have questions about it, feel free to private message me, if you have a fan fiction account. Anyway, that's it for the first chapter, hope you like it, be sure to review!