In the first encounter with the ego, the unconscious often manifests as chaos, as a wild beast that holds great promise and danger simultaneously. The ego, representing the world of consciousness, must be prepared to deal with this imminent danger adequately, or risk failing in the work, or even worse, being overwhelmed by powers and forces it could not contain.
In order to deal with the dragon, the ego must be fully prepared and protected. For this reason it appears as a knight in full armor, with sword drawn and ready. The knight comes from the world of the city and the castle seen in the background, but has entered the deep, dark inner world in order to confront the dragon-self. There are those who underestimate the powers of the unconscious, who naively approach the imaginative worlds with the expectation that goodwill and a pleasant smile will protect them and ensure experiences of light and love. There are others who believe that the imagination should be trusted above all else, and that the ego should only honor what it finds there, and never resist or try to transform it. Both views are misguided. The ego that approaches the unconscious must be armed and ready. It must be willing to hold its position at all costs, lest it be overwhelmed. It must anticipate not light and love, but the awful tension of the transcendent function. The goal is an ecstatic one, but the way to that goal is filled with terror and struggle. The heroic attitude of the knight is a necessity. As one alchemist exclaimed: "Know also that unless you seize hold of this Nature and rule it, ye will obtain nothing."
Jeffrey Raff, Jung and the Alchemical Imagination, pp. 100-101