Chan honestly hadn't been too worried when Neha didn't seem to come home, nor when she couldn't thereafter be found anywhere near the Lake. Sometimes wolves took off, followed a trail, a whim or just needed a breather. It didn't mean they were dead, or hurt, but then - Chan hadn't lost anyone suddenly like that, either. He knew it happened, but that was rare and as a runner himself, he'd rather give space and let others return on their own than panic and scour.
Hearing the pain in @Aleister's voice as he called repeatedly, searching continuously for his sister was what slowly ate at the Eastfall's heart and spurred him into action. Clearly their leader felt something was wrong, and he knew his sister best. Thus Chan started to search himself, including the various hazards he knew to exist along the mountain's spine. Just in case, but he hoped dearly he that he would find nothing at all before he found Neha's mangled corpse in any of them. It had given him the opportunity to climb the mountain's highest point once more, but had also led him directly into that storm that nearly took his and @Undertow's lives.
When he'd made it back, he'd been so exhausted by the trial that he'd only taken a moment to feed and slake his thirst before passing out in the communal den, sound asleep for hours.
Waking slowly, he stretched his long legs until the joints crackled. A satisfied groan left him, and the energy returned to him in waves. Warm and fed, all that plagued him now was a slight, ignorable ache throughout his body and the return of a parched tongue. Chan sat up at a sloth's pace, blinking the sleep away from his eyes. The sun was already gone; what did it matter if he took just a few more minutes to wake up?