Yes, a well-crafted and sharp sword, such as a katana, has the potential to cut through a human skull. The skull is composed of bone, which can be severed by a sharp and powerful cutting edge when applied with the appropriate force and technique.

However, it's important to recognize that cutting through a human skull is a challenging task that requires significant force and precision. The skull is a dense and robust structure that provides protection for the brain. It is designed to withstand impact and protect the delicate brain tissue within.

While a sharp sword can penetrate and cut through bone, including the skull, it would require substantial force, skill, and the right angle of attack. Cutting through bone, especially thicker portions of the skull, may be more difficult and may require multiple strikes or a specific cutting technique.

It is worth emphasizing that any act involving harm to others or oneself is illegal and unethical. The discussion of a sword's cutting capabilities should always be approached with responsible and lawful intentions, such as historical or martial arts knowledge.

If you have an interest in the art of swordsmanship or martial arts involving bladed weapons, it is advisable to seek proper training from qualified instructors who can teach you the techniques, safety protocols, and ethical aspects associated with the practice.