Tribulation渡劫
dùjié
A trial sent by heaven, most famously lightning, that a cultivator must survive to break through to a higher realm.
Heaven, in cultivation fiction, audits power. When a cultivator forces a major breakthrough, the world answers with a tribulation (jie): waves of heavenly lightning are the classic form, with heart demons (inner trials that attack resolve and memory) as the psychological variant. Surviving tempers body and soul; failing usually means death or centuries of lost progress. The verb form dujie means "crossing the tribulation".
Tribulation scenes are donghua's fireworks shows, and the mechanic explains genre behavior that otherwise looks odd: why experts hide their realm, why breakthroughs happen in sealed chambers or remote mountains, and why bystanders flee when storm clouds gather over a mountain peak. The final tribulation often gates ascension itself.