Sonic wasn't often fraught with nightmare. Quite the contrary; what with being a guy who let things run like water off a duck's back, he didn't have many psychological disturbances. He'd been through a lot, seen a lot, but ultimately it never amounted to anything that would 'haunt' him.
Except in one particular, very particular, instance. Sonic needed to crash after a certain day's events, badly, and now that he was managing to get sleep, it seemed even the night time wouldn't leave him alone. He stood on a cracked street, surrounded by a huge body of water, and behold towered over him a roaring monster, its tentacles lashing out at larger buildings. It wasn't the monster himself that was so horrifying, though. What made Sonic still, brought him out of his boast -- which started along the lines of 'c'mon, I've fought y'before, d'ya really think ya stand a chance against me?' (of course not questioning the logistics of seeing the monster again, since he was not acutely aware at this time that he was dreaming) -- were the screams that he could hear in the distance that didn't belong to the monster at all.
He tried to tap into the power of the Chaos Emeralds, the positive power that was, as he did only a day prior, but he found that he couldn't reach in the same way. His distress was only increasing the more that he heard those screams, knowing those people relied on him to save them, and he decided 'screw the Emeralds, that thing is going down with or without them!' Determination steeled his stance as he revved up his feet and immediately started running toward the thing, going faster than gravity wanted to act on him and therefore skipping over the water like it was solid land. This enraged the creature, which noticed him, and rose a wave in his direction. Sonic easily sidestepped this one, but Chaos was able to focus his attention in multiple directions, and the blue hedgehog was swept underwater by the second. He felt his vision fading, leaving him, as he desperately tried to reach out toward a bright light that appeared in the corner of his eyes--
... Only to land right on his rear end in front of a sparkling, bright gate, with a sky clouded by stars and beyond the gate, a water fountain. And now, instead of the screams of innocent civilians or the roars of a perfected god, he was met with silence. No one, at the moment, appeared to be here aside from him. Wherever 'here' was, that is.
Sonic blinked. Ooookay. This was weird. He lifted himself up to his feet, dusting himself off and taking a long look around. This place didn't look remotely familiar... How'd he get here? What about the people he was trying to save? Suddenly his heart kicked on overdrive as he started to dart around the gravel and the grass, looking hopelessly for some sort of portal that might've taken him here. He needed to go back to save those people!
"Chaos! Tikal!" He continued to circle around, before slowly coming to a stop, his ears drooping. "Knuckles? ...Tails? Anyone?" His shoulders slumped. This was great. He was somewhere he didn't know when people needed him, and while it was a nice place, he was all alone. What was he going to do now?