Lucifer led them to a hidden portal deep beneath Gotham, its swirling, chaotic energy reminiscent of the time rift that had brought Kei and Ignis to this world.

"This is it," Lucifer said, his tone uncharacteristically serious. "Once you step through, you'll be in the Void Nexus. Time, space, even reality itself will behave... unpredictably. Stay close, or you'll be lost forever."

Kei tightened her grip on her blade, steeling herself. "Let's do this."

The group stepped through the portal, and the world around them dissolved into a kaleidoscope of swirling colors and fractured realities.

As they landed on the other side, they found themselves in a realm that defied description. The ground was a shimmering mosaic of shifting patterns, and the sky was an endless expanse of stars, galaxies, and impossible shapes.

A towering figure loomed before them, its presence radiating power. Its face was obscured by a hood, and its voice echoed like thunder.

"Who dares enter the Void Nexus?"

Kei stepped forward, her voice unwavering. "We're here to save the multiverse. And we need your help."

The figure studied them silently for a moment before speaking.

"If you seek the Council of Eternity, you must first prove your worth. Only the strong, the wise, and the true may enter."

Ignis cracked her knuckles, her flames roaring to life. "Bring it on."

The figure raised a massive hand, and the world around them began to shift, transforming into a series of trials designed to test their limits.