The most logical sequence that explains the events leading to the spread of Buddhism during Asoka's reign is:
Asoka took over Kalinga by force. Asoka rose to power through civil war. Asoka adopted Buddhism. Asoka became a just and compassionate ruler.
This sequence showcases the transformation of Asoka from a conqueror to a proponent of peace and Buddhism after witnessing the devastation of war, particularly the Kalinga War, which led him to adopt Buddhism and promote its values throughout his empire.