Xue Wei grit his teeth as he persevered. He was feeling uncomfortable and sweat was beginning to bead on his forehead as he took deep breaths in an attempt to keep his stream of spiritual energy even while roaming through Bai Tianyi's body.
While he was trying to keep squeezing energy out of his body, he felt as if some sort of barrier was holding his energy back, trying to slow the speed of which it was leaving him, in an attempt to avoid letting the last few drops leave his body.
Even so, with the decisive actions of Xue Wei, the barrier was not enough to hold it back, and suddenly, as if a plug had been released, the final strands of spiritual energy left Xue Wei's body, alongside his entire cultivation base in this particular field.