Lore explains how complex Kayle actually is
She is defined as the aspect of Justice where just like the lady justice is blindfolded...
Kayle is also blinded by her own righteousness.. So she is willing to burn a country as a whole involving the innocent
Meanwhile her sister Morgana depicts the other side of justice...
The one with emotion and willing to forgive to give them second chance
So they are both right... but does things very differently