How was that proof he killed the former clan head... That's shaky as fuck. Clearly if I want to frame someone I only need to say they did it and why they would do it, and that would be enough to have everyone turn on them.
I hate these stories, from this day forth I shall never read another cultivating manga again. I am so tired of seeing the stereotypical shit that comes with each one. "Oh wow you're stronger than us, forget about the fact that we just tried to kill you~"
