For a Lawful Evil type. I once played a Fallen Knight who fell due to love of King and country.
His homeland was being torn apart by intrigue and people were growing increasingly paranoid, stealing from each other and participating in witch hunts. So he vowed to become the evil people would fear so they would stop preying on each other.
This culminated in him brutally murdering the king at a banquet to make himself a target and gaining levels in Antipaladin (previously was a Fighter).
So he started from a good place and well, things just kind of spiraled out of control from there.
Basically all he wanted to do was unite his people, and if kindness wouldn't do it, a looming threat would.