His original plan had been to use the grasp of the broader situation in the Northern Lands that he had gained through Tribulation Divination, along with the many secrets and pieces of intelligence he held, to complete his accumulation of the "Muffled Crow in Ambush" image, then break through to Inner Vision in one stroke.
As for the Errant Thunder Drum, that Spirit Artifact of "Contrary Thunder," he had not initially considered it something he absolutely had to obtain.
Having the Errant Thunder Drum would be better, allowing him to carry out his Mountain-Smiting, Temple-Breaking plan without waiting another thirty years. Without it, he could simply head overseas after his breakthrough, wait until the matter of Ancient Chu's Southern Return in the Northern Lands had settled, then come back. He could accomplish his goal either way.
It was only later, when the blessing of "Li Thunder" upon the name "Li Yaoshi" made his concealment ever more secure, and he became entangled in karma with Quan Yong, that he truly resolved to seize the Errant Thunder Drum.
After all, if he could accomplish the feat of Mountain-Smiting, Temple-Breaking while accumulating "Muffled Crow in Ambush," even he could hardly estimate how great the rewards would be.
From beginning to end, he had come to the Northern Lands to involve himself in this turmoil involving Purple Mansion cultivators for just one purpose.
To complete his accumulation of the "Muffled Crow in Ambush" image, form his Dao fruit, and break through to Inner Vision.
Breaking through was something he could accomplish on his own. Using Tribulation Qi for Tribulation Divination was simply too poor a bargain.
But things were different now. The situation had changed.
At present, he stood in a delicate gap between opposing pressures.
Perhaps some Purple Mansion cultivator would notice him