Lin Shen followed Tie to study the Lawless Heaven technique. According to Tie, you must first be able to sense the Order Law's existence before you can break it.
Rules exist; breaking them leads to Lawless Heaven.
If you can't even sense the rules and act recklessly, that isn't Lawless Heaven. It's just the ignorance of the fearless.
Thus, the first thing Lin Shen had to learn was sensing the Order Law's presence. Nirvana Beings could perceive Law Power, and as long as they didn't attempt to manipulate or merge Law Power, they wouldn't ascend to become Immortals.
At the Nirvana Level, the more laws one comprehended, the clearer they became—or sensing laws that others couldn't perceive could lead to becoming even stronger in their Immortal stage.
Sensing others' laws typically resulted in mastery of the Past Law, but this was a necessary process for everyone to undergo.
