
Let's hear from plausible to ridiculous
I got a few so far
One
The hero after defeating the demon king, nobility persecuted Lancelot because he was probably my gaining just as much popularity and scapegoats him for a stupid reason
Two
The hero was in love with ange as well and they fought over her or he tried to do something causing Lancelot to kill him without another choice
Three
Someone betrayed the party and framed Lancelot