[Single female lead + cultivating immortals by taking disciples + founding a sect + hilarious and absurd + sensible, doesn't seek death + decisive and ruthless, because they're all demonic cultivators]
Li Chen was born into a family of two demonic cultivation powerhouses, with an impressive background.
His birth triggered a disturbance in spiritual energy, yet he was judged to have no talent.
Sixteen years later, his disciple-taking System activates. Following his own ideas, Li Chen successfully establishes the Sandstorm Sect, which is clearly another demonic sect. Its disciples all seem a little too bloodthirsty.
A marriage arrangement brings him together with Feng Mengli, but this woman seems a little too forward.
Meanwhile, Li Chen keeps taking in disciples, improving their strength, and cultivating step by step until he reaches the peak.
If you enjoy stories about building up a sect and raising disciples, be sure to give this a try, though the pacing is rather slow.
The starting point is that the sect leader is so weak that it's boring to watch.