The Easter egg at the end of the movie

The old man from the Limitless Demon Sect still had some lingering fear while talking about the 'rumored True Monarch White'.

"The rumored True Monarch White?" Daoist Priest Weiwei had a confused expression on his face. Up until now, he had practiced for a little more than 150 years... in other words, True Monarch White had gone into secluded meditation before Daoist Priest Weiwei had started practicing, and had come out just recently. Therefore, Daoist Priest Weiwei was unaware of the rumors surrounding True Monarch White.

The old man from the Limitless Demon Sect started recalling. "He's... a very fearsome enemy."

The old man recalled an event from several hundred years ago. Back then, he had still been a Fifth Stage Spiritual Emperor, and he'd gone to explore some ruins that a wandering foreign expert had left behind alongside six other junior and senior brothers from the Limitless Demon Sect, also of the Spiritual Emperor rank.