The Mystic Sect, centered on the master-disciple tradition, values rules the most. The sect leader's orders are something ordinary disciples dare not defy.
However, Tie Dan is no ordinary disciple.
He has always had a vengeful nature, with long-standing discontent toward the Inner Mountain, growing by the day. As early as his face-to-face debate with the Sword Monarch, his grievances were already visible, just a step away from shouting, 'How can we improve the Sword Sect by associating with such worms!'
Thus, Tie Dan honestly does not wish to return to Nine Yin Mountain. After all, becoming independent after leaving the mountain isn't rare in the Mystic Sect. As long as one finds a place with a Spiritual Qi Earth Vein, digs a hole, and goes into seclusion, one can hide for hundreds of years where no one can find them. Who knows if they are dead or alive; this is called the Hidden Immortal Sect.
