My Goddess is Good at Pretending
Imagination was the eye of the soul, the beginning of creation. Despite her immense power, the Supreme Goddess of Mysterious Origin had to seal herself after saving the world from the threat of destruction. However, she was sent to another world by the universe's will. Ely was a girl suffering from partial memory loss. She was known as the shrine priestess of the Sacred Mountain. One day, she received the holy mission to unseal her Goddess Master. She got her priorities straight. However... The pets she adopted became the Demon Kings, capable of suppressing the world. The tree she planted became the World Tree, forming a bridge between heaven and earth. The passerby who received enlightenment from her became the Sage who led the entire generation. The disciples she nurtured became bigshots known across the three worlds. When she looked back... The street painter who pestered her for her handicrafts and paintings turned out to be a God. The young priestess she recruited was actually the number one saintess from the Divine World. She was known as the holy saintess. Yet, she still referred to herself as a mortal.
Training Hall Space
The simulated realm was the newly refined private realm imbued with Elysia's divinity and absolute domain expansion. Countless corrupted cosmic creatures above the 11th Rank were prepared in the training hall space in advance, and they would respawn endlessly as long as there was enough energy for it.
The stronger monsters would await at the depths. The monster's rank also determined the total score students would receive on their hunt.
As for how the realm could empower itself, the technology was similar to Vrelenia's Cube Island to self-sustain.
However, since Elysia's imaginary divinity and absolute domain were installed there to regulate everything, the dispersing energy would be absorbed by the space and transferred to Elysia. It would become one of her new farming grounds, the shortcut to fill her SP and MP.