A savage personality is part of what makes a villain truly formidable. Clavius and Zelda are two of the most savage! This is why:
A Savage Holds Hostages
A savage doesn't care about using innocent people to get what they want. Zelda has some fun while keeping Odette as a hostage. Clavius does the same thing; he fools on Jean-Bob and his friends to to get the orb.
A Savage Tries To Steal What Is not Theirs
A savage believes in working smarter, not harder, all the while having zero conscience. Why work hard to get something yourself when you could just take it from someone else? Zelda breaks locks to steal what is inside furthering her plot to steal the forbidden arts. She also steals a letter from Derek's hand, who believes he is talking with Odette. Clavius invades Odette's dining hall and says he is looking for the orb of the forbidden arts, demanding she give them to him.
A Savage Uses Powers To Do Evil
When given magical powers, many people would use them to help themselves never hurting anyone else. The best people upon discovering the powers would use them to help other people and the communities they live in. Savages like Clavius and Zelda not only have these powers, but use them to harm other people in their pursuit of evil causes. Clavius uses his fire conjured by the forbidden arts to hurt Derek, while Zelda uses her magic to fight with him and threaten Odette.
A Savage Deceives Others
If a savage were to tell the truth about their plans and desires, no one would help them. if not for the common good than simply for self preservation. What is a savage to do then when a willing participant is needed for their evil plot? They lie of course! By deceiving others they can get them to cooperate under false pretenses. Its a truly savage way to get what they want. Zelda plans to play-act pretending she is in distress to gain Lord Rogers sympathy. Clavius dresses up as a clown, and deceives Queen Uberta in order to kidnap her. She thinks she is climbing into a hot air balloon to have a regular balloon ride for her birthday when it is really a trap. Zelda once again fools on Lord Rogers, and hits him with her head.