Epic of Caterpillar

Before Kireina were to arrive in Genesis, Truhan and Celica led their army towards the breach between worlds, connecting Genesis with the Spirit Plane. This wasn't a reckless act, or well, it was, but not without reasons. Armies of millions of Divine Spirits, raging from Great God Ranks to Pseudo Supreme God Ranks flew constantly towards their "territory" the entire area that Kireina, Flora, and Aura protected within the entirety of the World of Genesis.

And their aim? To steal the Yggdrasil Trees Kireina held in her Divine Realm and probably those of Flora as well, all while they constantly attacked allied Realms that were barely holding back, some already having fallen before the might of these strange, semi-transparent entities that weren't at all like the Spirits they remembered about, such as Brontes or Nereid.

No, these creatures were utterly otherworldly, resembling monstrous beings that looked like half-insects and half-humans made out of glass that shone with several bright colors. Sometimes, it felt as if they existed in several different positions at the same time, making theme extremely alien even for such a world as Genesis, filled with fantastical creatures.

Their armies of millions descended like swarms of light, beginning to take away all energy they could harvest, this included living beings, their souls, and even their bodies. Whoever controlled them, they were hungry for power.

Leading a huge army composed of the strongest fighters, Truhan and Celica braved the army of Otherworldly Spirits, at their side the Monkey-kin Team, the Elemental Lords, the former Inhabitants of the Grand Forest, several Vampires, and even the Undead Team joined them, with hundreds of other soldiers coated in mechanical magic armors and strengthened with Totems.

Their bravery, strength, and combined power did work, as they were able to push the enemies all the way back to their Plane, several other Gods joined their fight, protecting their Realms. However, they never meet with Freyja, Poseidon, or anybody… Because much like them, before they could return with everybody else, an enormous flash of light surged from the portal leading to the Spiritual Plane, and like a black hole, it absorbed them inside in a catastrophic explosion of light.

TRUUUUUUMMM…!

They were completely powerless as they were sucked into a whole different dimension. Truhan making sure to hold his beloved wife tightly with his arms as the two braved the unknown, their armies close by.

When they opened their eyes again, they found themselves in a world filled with the rare Spiritual Energy, an energy that Spirits were mostly made off. The air was incredibly thick to the point it was hard to breathe, and the ambient mana or divine energy was also tremendously high.

A world made out of beings that were just compressed energy had to have such enormous quantities of energy itself… They didn't knew how long they have been there. But when they woke up, Celica and Truhan were the firsts to glance and wonder around their surroundings.

"W-Where are we?" Celica wondered, looking at a world that seemed slightly similar to Genesis, yet twisted.

There was no Astral Road, but an endless blue sky with a sea of clouds beneath. Countless floating islands spread everywhere, and huge spheres of light resembling giant bubbles wandered around.

Each island was covered on large quantities of shining, bright crystals, which at closer inspection were actually Spirit Stones of the highest rarity.

"Did we… fell into the spirit world?!" Asked Truhan, glancing around with his gigantic body. "Ugh… the air in here is terrible! And our armor got completely destroyed."

"Yeah, the air is filled with energies, especially spiritual energy and mana… Wait." Celica had quickly imagined that the reason why these spirits wanted to steal everything with energy was to fuel their own world, their existences might had depended on it. "Could it be because of that?" She explained it to her husband.

"Maybe… But that doesn't mean they aren't bastards for trying to destroy our world." Truhan sighed. "Are you okay? No wounds?"

"N-No, dear, I'm fine." Celica stood up, glancing around her surroundings in wonder once more. "This world is very bright, ugh, my eyes… Anyways, we have to move. We landed somewhere… We have to find everyone else!"

"Yeah, I can sense some presences to the far west of this… floating island?" Truhan muttered. "I just hope everyone else is doing alright."

"Me too, honestly." Celica said. "I've been trying for a while, but I can't talk to anybody through telepathy. The thick atmosphere of spiritual energy and mana in this place makes it impossible. Well, we should be thankful we can actually survive here to begin with."

"More or less!" Truhan laughed. "Thankfully we left our kid back on Kireina's Divine Realm. Even if she's gone for a while, Rimuru and the rest will protect them. With that, we don't have anything to worry about other than ourselves… And well, our companions left here."

"You're right." Celica nodded. "Kireina-sama… I'm hoping for her return, wherever she is!"

The two Giants, or well, Titans at this point, both over a hundred meters of height in their base forms, ran across the utterly titanic Floating Island, perhaps half as big as the Realm of Vida.

The only thing they saw for a while was endless green forests, enormous and strange-looking trees, and fruits they ate and found too sweet, though they didn't had anything else to eat anyways, and also crystals, crystals everywhere.

Thankfully, their weaker troops had all been summoned inside their Divine Realms, so only the big shots, which were the strongest named as generals were outside, and were thrown around here, somewhere. Their divine reals were still safe if they wanted to get in, but they felt like it would only waste time.

"These crystals are really valuable and infused with energy, might help us get some stronger potions or weapons." Celica ran across the landscape with Truhan while kicking the crystals and storing them inside her divine realm.

"Look!" Truhan pointed at the distance, the two giants eventually found some of their friends, a group of monkeys on the floor unconscious, and a single monkey covered on wounds fighting a large group of beasts overflowing with spiritual energy…

"That's Kizuato! Let's hurry!" Celica cried, the two giants rushing there.