In Jasper Academia Online (JAO), the fundamental energy system known as Essence is at the core of every character's power. This unique energy governs the abilities and strength of individuals, allowing them to manipulate the world around them. Essence comes in two distinct forms: positive and negative, and both are directly tied to the emotions of the user. Positive Essence is fueled by uplifting emotions such as joy, love, courage, and hope. When a character draws on positive Essence, their abilities become more focused, harmonious, and stable, often leading to healing, protective, or constructive effects.

On the other hand, negative Essence is driven by emotions like anger, fear, hatred, and sadness. This form of Essence is powerful but volatile, capable of unleashing destructive forces. While it can grant immense strength and raw power, it often comes at the cost of control and stability, as negative emotions tend to cloud the user's judgment. Characters who tap into negative Essence are often driven by personal struggles or dark desires, leading to devastating attacks and chaotic effects that can affect both the user and their surroundings.

The balance between positive and negative Essence is crucial within JAO. Some characters may favor one form over the other, while others learn to balance both to enhance their versatility. Those who can master their emotions, harnessing both forms of Essence, can achieve great feats, becoming a force to be reckoned with in the world. However, those who allow their emotions to control them may find themselves consumed by the very energy they wield, illustrating the dual nature of power in JAO.