The second tear was shed for his father.
It was when he left Li City, through the Soul Covenant of someone from the same era as his father, that Chu Mu, having become half-demon, plundered his memory and saw his own tragic past!
Chu Mu knew very well that his father, when he was young, must have been working tirelessly towards the highest altar of a Soul Pet Master, something that was worth a lifetime and life's pursuit.
But alas, his father's life was cut short during his youngest and most brilliant years, all his soul pets were forcibly released from their soul contracts, and his three main pets were sealed in the Seal Tower...
Even in the end, in order to let their master step on the path of a Soul Pet Master that had been cut short and rise again, these three main pets chose self-destruction within the Seal Tower, releasing their master's soul.
This tear was shed for his father's tribulations and for his father's three great soul pets!