Because Dong Tianyu usually did not use Sword Flight and chose Wave Rider as his vehicle instead, he rarely used the Companion Spiritual Treasure. The few times he did, it was merely as a temporary solution, so he did not store much on the Jade Ship.
For this reason, Dong Tianyu was unaware that when retrieving the Companion Spiritual Treasure, objects not belonging to the Companion Spiritual Treasure would not be included in the retrieval back into the Sea of Consciousness.
Had it not been for obtaining the dark green Mysterious Core this time, Dong Tianyu might have discovered this issue much later.
Since the Mysterious Core had been devoured by the Companion Spiritual Treasure, Dong Tianyu now needed to make a choice.