1. Martinet : Discipline
Tyrant: A cruel ruler- someone having characteristic opposite of compassion
Martinet: a strict disciplinarian
Sceptic: a person inclined to question or doubt accepted opinions
Egotist: self-seeker
Reprobate: an unprincipled person
So, only for the first one we have a similar characteristic for the two words, while for the other three we have opposite characteristic.