Wilhelm is a calm and extremely intelligent individual. Even at times of great distress, he can calmly and quickly analyse the situation and come up with a solution even when everyone else, including more experienced soldiers, are at a loss of what to do in the face of superior opponents. His strategies are often unorthodox, cunning and very unpredictable. Wilhelm does not usually speak much and rarely expresses emotions of any kind.
He is decisive and dictates his actions with plain logic rather than emotions. He states that he is not interested in emotions such as hate or anger, seeing them as emotions that are manipulated to incite war. Wilhelm's own lack of expressiveness of emotions may stem in part from this belief.
Death Magic is a Black Art that allows its user to kill any living thing they desire in an instant. This Magic seems to be uncontrollable at times, causing it to burst out randomly, killing anything within a certain radius around the caster. However, when the user forgets the value of life, they can fully control their Death Magic. Certain Magic Items can protect people from Death Magic, such as Natsu Dragneel's scarf. Moreover, there are certain enchantments that null the effects of Death Magic such as the one placed on all citizens of Camelot.
- Death Wave: This usage of this spell creates a dark wave that kills everything in the user's immediate vicinity.
- Death Orb: A spell that, when used, destroys everything in its path.
- Death Pillar: Wilhelm swipes both of his arms in a circular motion until the bottom of his hands meet. The hand on top has the index and middle fingers pointing upwards, while the other hand has the little and index fingers pointing downwards. While doing this, he is surrounded by a dark aura. This spell creates a huge vertical explosion, and it's blast radius is seemingly controllable.
Nikyu Nikyu no MiEdit
The first and foremost strength of the fruit, as demonstrated by Wilhelm, is that the user is able to push virtually anything they touch and send it flying at an extremely high speed. This includes both tangible materials such as people and objects, and intangible materials such as air, the ghosts generated by the Horo Horo no Mi user and the sensation of physical pain. This power offers the user an incredible advantage in battle, allowing them to deflect any attack. They are also able to harness their abilities to perform offensive maneuvers, such as repelling the very air around them at very high speed. These attacks are so powerful that they can leave paw-shaped imprints in rock.
One misconception about the powers of the Nikyu Nikyu no Mi is that it gives its user the ability to transport at will. However, this assumption is incorrect. Rather than teleport, Wilhelm uses the incredible speed of his Devil Fruit power to propel himself across certain distances, the speed of which is near instantaneous.
While the user is able to deflect attacks, they can only do so by using their bare hands. If the user's hands are otherwise occupied, being caught off guard for instance, they will receive damage from an attack that could have been otherwise averted.