The first half follows the manga: students hunt Kishin eggs, the conflict with witches builds, and the Kishin Asura is set free from his seal beneath Death City. His release spreads madness across the world. Soul also has to deal with the black blood inside him and the pull of madness in his own mind.
After episode 38 the anime writes its own path to the ending. In the finale, Maka faces Asura, who taunts her ("Go on and stab me... but what about you?") and insists madness will always come back for countless reasons. Maka's answer, "Who gives a damn?!", rejects the entire logic of fear. Her friends then name her defining trait: bravery. Asura's last words, "Everybody huh... then it's just like madness," suggest that courage spreads between people the same way madness does. Looking back, the series was building to the idea that its central weapon is courage, not soul-power.