Guilt
Lex woke up after a long comfortable sleep. He rubbed his eyes and sat, resting her back on a pillow. He looked around at his surroundings before he remembered where he was.
'Ah! Yes, we all were sent to the hospitals.' Lex thought as he looked at the blue painted room of the hospital. His bed was right beside the window so he could even feel the cool morning... evening?... breeze, fluttering his crimson red hairs.
He sighed and looked to his other side where a young girl with long auburn hair was sleeping. Her breathing was regular, showing she was in a deep peaceful sleep. Her lips were tugged upwards, making Lex have a guess that she was having a good dream.
Lex was mostly free since he was just exhausted. Well, he was injured but Duel of Fate had healed everything except the mental fatigue that built up. Making the domain itself was very exhausting and stressful, after all. So, Lex had a good sleep after everything resolved.