Lin Wu himself went back underground and followed from there. One of the restrictions that Lin Wu had in controlling the man like this was that the range of this was very short. Lin Wu not only needed his spirit sense for it to work, but the cellular manipulation link that his body had with his crystals was also needed.
With just his spirit sense, he would not be able to control the man, not to mention if he went past a certain limit, the crystals that were detached from his body would become lifeless.
This was something Lin Wu had only gained recently after his upgrades to the innate skills. Being able to control his body parts as crystal when they were detached was only possible in the Crystalline form, though.
He could not do the same in the organic form and would just end up injuring himself instead.
