The hedgehog sensed a sudden change within Tikhaos. The tormented spirit was losing chaos energy at a rapid rate, even though he'd made sure to overload her with enough chaos energy to devastate the entire planet for centuries. Alas, before he had the chance to even frown and ponder the matter, a heroic duo elsewhere in Portal dealt the final blow to the watery behemoth's brain, expelling the last of the excess energy from Tikhaos, reverting her back to her original form.
The water that had once engulfed the city was absorbed back into her being, scattering any rubble it carried and further damaging buildings already affected by flash-flooding. Miraculously, Castle Mobius, the place where the entire ordeal began, was mostly intact, save for a crumbling kitchen atop what was once Tikhaos' former prison. Amidst the rubble, a dark figure barely visible in the gloom stood gobsmacked, his eyes widened in surprise.
"How… How did this happen?!" he thought aloud, "neither sonic nor the rest of the Freedom Fighters are even capable of this anymore!"
Lost in thought, King Shadow failed to realise the state of his surroundings until a slate from the devastated roof fell onto the ground behind him, making the stoic dictator jump in surprise. Immediately he tensed and spun around, swiping at the air in front of him, his eyes widening in surprise as he realised that he was alone in this ruin. He sighed, mentally berating himself for being so jumpy.
He glanced around his surroundings, taking in the destruction that he single-handedly caused. Coming to the realisation that the castle, which was miraculously still standing, could come crumbling down on him at any moment, he bid farewell to his former home and escaped into the night.