Answer:
From the experience in the Kalinga war a new Ashoka emerged, a sovereign who, truly repentant, wished to purify his soul in the face of the desolation he had caused with a single order from him. This was expressed in many of his edicts engraved on stone. In these edits, you can apprehend your regret and your intention to convert to Buddhism. A clear example is:
«The beloved of the gods felt remorse for the conquest of Kalinga, because when a country is conquered for the first time the killings, death and deportation of people are very sad for the dear of the gods and weigh heavily on their soul».