The Demon is a central theme of Vrubel's work. The artist returned it throughout his career, embodying the image in painting, drawing and sculpture. The image of the Demon first entered the artist's mind during the Kiev period, when he was sketching murals for the Vladimir Cathedral (1884-1889). As he pondered the challenges of monumental painting, Vrubel studied Byzantine mosaics and frescoes. In a time of a deep crisis in faith and religious searching, thinking about the spiritual ideal, the artist did not find it in the image of Christ, although he did make some attempts. The era of Art Nouveau and Symbolism made beauty an absolute, a higher truth. Vrubel created the image of the "Light" Demon, attempting to deviate from the Christian interpretation of his hero as the personification of darkness, but he did not accept old traditions or contemporary interpretations of European Symbolism. He said: "The Demon is misunderstood; he is confused with the devil… But Demon is Greek for ‘Soul." Having passed a complex path of rethinking literary prototypes (Hamlet and Ophelia, 1884, State Russian Museum; Hamlet and Ophelia, 1888, State Tretyakov Gallery; polyptych on the theme of Goethe's Faust, 1896, State Tretyakov Gallery; Head of the Demon, State Tretyakov Gallery) the artist departed from them.

Vrubel first imagined something "demonic" during his 1889 trip to Moscow: "…A half-naked, winged, young, moody and thoughtful figure sits, hugging his knees against the sunset and looks at a flowering field, where branches rotting under flowers stretch." The first attempts to capture this vision were lost, and the small watercolor Demon (Seated) (1890, State Tretyakov Gallery) is perceived as the closest to it. But Vrubel had yet to make his monumental Demon Seated (1890, State Tretyakov Gallery). Vrubel found his hero to embody the creative spirit of the era, which "aspired to live, touching the shroud of divinity, if not with a praying hand, then with a feeling of beauty in its imperishability and eternality." (S. N. Bulgakov). Vrubel alluded to the image of the ancient Demon, the Socratic "divine voice" that in Platonic philosophy is interpreted as "an intermediary between people and gods, leading man down a path of passion and death to knowledge of the immortal and higher beauty." (Vladimir Solovyov, The Vital Drama of Plato). "Suffering and mourning, yet nonetheless powerful and grand," in the words of the artist, he personifies the eternal struggle of the human soul, "not finding an answer to his doubts either on the earth or in the sky." The theme of spiritual turmoil interweaves features of sacrifice and grief. Vrubel's Demon is closest of all to the poetic images of the philosophy of Friedrich Nietzsche, his Christ/Dionysus, and reflects a desire to reconcile Christianity and paganism characteristic for religious thought of the period.

The superhuman features of Vrubel's Demon are neutralized by his aloof and contemplative nature. On the other hand, the high degree of spiritual concentration in Vrubel's hero echoes Schopenhauer's teaching about the resistance of peaceful will with the help of ecstatic creative contemplation, opening the mind to higher forms of the Beautiful, as absolute ideas, that which he called "the highest good and state of the gods." Thus, the Demon to a considerable degree reflects an abstract idea of a certain spiritual state, rather than a personification of a certain character. Vrubel's method of mystic, creative intuition is parallel to images from Solovyov's poetry, penetrated by a premonition of an "unknown god":

The Demon's soul is bound in his body, like an enormous stone that flows in the rays of the sunset, rising on the peak of the cliff. The composition is full of inner tension. The horizontal format of the canvas is opposed by the dominating vertical figure, the upper part of the head is cut off by the edge of the painting. The powerful shoulders and arms, seemingly cast in molten bronze, recall the figures of Michelangelo. The contours of the hulking figure suggest a blooming flower or a chalice. These contours repeat several times in the space, bordered by a gesture of the hands, which creates an impression of a huge energy growing from within. His knees, enclosed by his hands, form a heart-like, crystalline shape. The multitude of lines strengthens the impression of constantly transforming shapes and their vivid multiple facets. His hands are tensely folded, and yet resemble broken chains. The Demon's arms remind us of the powerful wings that the character no longer has. Covered in shadow, the Demon's profile is a contrast to his massive body, and seems to belong to another creature. He is "the son of heavenly abundance and earthly scarcity" (Solovyov, The Vital Drama of Plato). The turned head and dark, flowing tresses create a feeling of flight. His facial features seem to melt in the rays of the setting sun, in the process of transformation. Vrubel avoids painting idol-like stiff features. This giant contains huge energy, and yet he is filled with melancholy.

Directing his gaze at the rays of the setting sun, he remembers the world of heavenly harmony he left behind, and grieves from the feeling of the imperfect beauty of earth. A pearly tear glitters on the Demon's cheek. His yearning for absolute beauty is not in vain. It carries a creative blast. The world around him is illuminated by a new, fantastic glow. The flowers surrounding his figure transform into crystals, as if fused in a new substance transfigured by light. The Demon and the beautiful flowers form a unified whole.

Vrubel's painterly manner suggests a titanic emphasis on form, which lends the pathos of cutting spiritual energy out of fossilized matter. Powerful brushstrokes of the edges are in perpetual motion. The artist creates an imperishable supersubstance of painting, a kind of philosopher's stone. Layering paint with a palette knife, Vrubel synthesized oil painting, sculpture and mosaic. The key to Vrubel's unique painterly method as displayed in Demon (Seated) is his special device of stylized crystal faceting. The complex play of form in the painting helps the artist avoid superficial allegories. The struggle of the visual fabric gives birth to an impression of a constantly transforming symbolic image, like a crystal. This results in a paradox, striking in its aesthetic tension, in which the protagonist's hermit-like contemplation and noble inertia are in opposition to the artist's creative drama. Vrubel does not give his image a sense of completion, as if he is afraid to distort it.