Once He Yuan arrived at the converging peak, he noticed that there was an extra barrier surrounding the peak. Elder Mo had gone into seclusion. In the storyline, this was because he'd found a demonic technique that was suitable for breaking the formation sealing Mo Sheng's demonic half.
Da Hei proceeded to go over to the immortal cave in elder Mo's courtyard. The immortal cave was basically a cave underneath elder Mo's courtyard with layers upon layers of formation that prevented entry from others.
The only exception was Da Hei seeing as he was elder Mo's spirit beast and their souls were bound together. He Yuan would've loved to witness elder Mo in action but it was a taboo to show up in a cultivator's immortal cave unannounced.
It could distract the cultivator and lead to fatal consequences. He Yuan shrugged. It wasn't as if he could break past the high level formations anyways so he changed direction and headed towards the spiritual lake.
